There are many factors that can affect the PCB cost from the concept to the pcb manufacturing and assembly. Since the begin, the pcb layout mostly drive the printed circuit board cost, because once the engineer have a functional schematic, the PCB designer has to do the layout, when the layout process finished, the PCB manufacturer will start to produce the circuit board based on the design.
Now let’s introduce some factors that can affect the PCB price:
1. PCB and Panel Size
This is one of the biggest factors that can affect the PCB price. Because a smaller area means a reduction in material cost. For panel design, there are many different permutations but typically most costing is based on this panel size. Obviously smaller PCB designs will have a higher volume that will result in a lower piece price. For high-volume production, panel utilization becomes a critical aspect with respect to PCB cost.
The bigger the surface area is, the more it will cost you. So you even pay for the waste part (in faded green) that is thrown to the bin after assembly. If possible, place the boards on the panel closer to each other to reduce waste and cost.
2. PCB Layer Count
Generally speaking the more layers means the higher the cost. Because you add more layers to your design, the more material, like prepreg and copper, and more production steps, like etching, pressing, copper plating etc. all add the cost. This cost factor also depends on the complexity of the PCB design and differs from manufacturer to manufacturer. However, reducing layer count does not always reduce overall cost, since doing so could involve more complex technology and aggressive design practices.
3. PCB Material
The common material for printed circuit board is FR4 material with TG 130-140. But when the circuit board is used in special environments such as RF, Microwave, high speed, high temperature or high moist and so on, it need special material which will cost more than standard materials.
4. Copper Weight
Generally, the copper thick is 1oz, the thicker the copper is, the more expensive the circuit board is. When copper weights increase the PCB Fabricator’s etch-factor becomes more critical and harder to control – this adds cost. Another disadvantage of using thicker copper is that you have to maintain greater spaces between traces. But the the copper is very thin(less then 0.25oz), the process will be expensive as well.
5.PCB Holes Size Quantity and Type
Smaller Hole size is more difficult to manufacturer, it need smaller drill bits, or some smaller hole need to be laser drilled, which cost more. Also smaller drilled holes require tighter control and monitoring to ensure clean and smooth drilled-hole walls that will allow for plating chemistry to pass through. If it has many holes in one piece circuit board, the price will increase as well.
Buried vias are plated holes that connect inner layer circuitry but do not connect to outer layers. Blind vias are plated holes that connect outer layer circuitry to inner layers but only from one side. Both of them require extremely tight layer to layer registration, both of the vias require repetitive drilling, de-smear, copper plating and lamination processing, so it add the cost of the printed circuit board.
When PCB’s are manufactured and shipped in an array format, sometimes individual boards are deemed defective and are physically marked accordingly – generally with a big ‘X’ on them. If you don’t accept the X-outs circuit board or have higher requirement about the X-board, the manufacturer have to run more panels to ensure the entire order is filled, it increase the cost.
7. E-test fixture
When the quantity for pcb board is large, you can consider the E-test fixture, it just need to pay at the first and can save the cost.
8. Special Requirement
Some clients have special requirement such as copper grouting hole, impedance, plate edge metallization etc. will add the cost.
To sum up, you should consider the hard cost drivers during the design and layout stage. Select the material type carefully and try to avoid waste as much as possible.
When sourcing a prospective PCB vendor, a top-quality shop like 86PCB is capable of offering all of the above processes, we will give you suitable suggestion and save your cost. If you have related project, you can contact with us, looking forward to our win-win cooperation.