Engineer shares the main factors determining the assembly cost of multi-layer boards!
 
In an increasing number of miniaturized products, multi-layer PCBs have been widely used in multiple industries that use complex PCBs. However, there are many factors that determine the cost of multi-layer boards.
 
Material selection

The materials used to manufacture circuit boards have a significant impact on their cost. When choosing PCB materials, several factors need to be considered, such as:
Do you need a circuit board to withstand higher operating temperatures? For circuit boards that need to work at high temperatures, it is necessary to use copper-clad laminates (CCL) and PP materials with high glass transition temperatures. There is a risk of resin delamination when using materials with low Tg, which can damage electrical connections when the temperature rises.
Another major factor to note is signal performance. Therefore, the choice of material depends on whether the material will promote uninterrupted electrical signals.
The mechanical properties of the board are also crucial in ensuring that it can withstand any foreseeable mechanical stress and strain.
   
Circuit board size
The size of the PCB is also a determining factor in its cost. The substrate is usually charged by size, so large PCBs require a certain fee to be paid. However, this does not mean that the standard rule of smaller PCBs being cheaper will be adopted. This is because in small PCBs, wiring time and the labor involved can be very time-consuming. The size of PCB and the processing time involved will both affect the cost.
 
PCB layers
Of course, another major determinant of cost is the number of layers. For example, the double-sided PCB you mentioned means that there is no need for copper foil coating and no additional layers that need to be processed. Therefore, based on experience, the more layers there are, the more resources and time are required for the manufacturing process, and the higher the cost.
 
Surface Treatment
The choice of surface smoothness can also affect the cost of multi-layer PCB manufacturing. Some finishes are known for their quality and longer shelf life, which obviously increases costs. For example, choosing HASL surface treatment has a very low cost. In contrast, the cost of ENIG coating is slightly higher. When it comes to HDI PCB design, multiple finishes are often required, which in turn may affect costs.
 
Types and densities of holes
The price of multi-layer PCB manufacturing depends on the following factors:
Opening size
Its density
pass
 
For the size of the hole, the standard aspect ratio to be followed is 8:1. If the size of the hole changes, it means that you need to use customized tools to meet your customization requirements, and you will soon need to pay additional fees. Similarly, although it is normal for the pore density to be less than 120Kpcs/qm, any such changes will once again increase costs. Similarly, the cost of standard through holes is the standard cost, but if the circuit board requires any blind holes and buried holes, the cost often increases.
 
Trace width and spacing
To avoid overheating, sufficient line width should be left on multi-layer boards. Therefore, engineers can consider whether to increase the wiring width or add additional solder, both of which will increase the cost of materials and related work.
 
PCB Thickness
Thicker materials typically have higher costs in production, lamination, and processing into PCBs. If the design is complex, the cost will increase. Another aspect that affects prices is aspect ratio.
 
Requirements for any special process
If there are any unique design elements that require any special craftsmanship, it will have an impact on costs. Some processes that may affect costs include impedance control, carbon ink, blind holes, edge electroplating, depth control, halogen-free materials, etc