When you are getting closer to PCB fabrication, the end cost of such electronics is your biggest concern. So, to minimize the unnecessary expenses, you need to know well the cost factors affecting the end price. Let’s discuss the unavoidable expenditures and the ways to reduce them.
Factors That Affect the Cost of PCB
For starters, it is essential not to let moisture in during the manufacturing process.
1. Material choice
The first decision to make regarding PCB fabrication is laminate material to use. The conventional options here are FR-4, Rogers laminate, Teflon, Ceramic, and others.
The mentioned significantly differ in their properties, scopes of applications, and prices. It is not always (never) that the most affordable material from the no-name brand is the best option, so choose wisely.
2. PCB size
Well, all the manufacturers offer three standard PCB dimensions: 18 X 24″ (457 x 610mm); 18 X 21″ (457 x 533mm); 21 X 24″ (533 x 610mm). Ordering any of those will not affect the price significantly.
However, the cases of constructing custom or micro PCBs are not unheard of. Such options will naturally result in an instant price surge for obvious reasons.
Besides, you should consider the panel utilization, so it uses the board space effectively. Sheets of unseparated PCB sheets may have, for example, two rows and three columns. Having 1 column and three rows may not be unavoidable but will result in higher margins and ineffective use of material.
3. Number of layers
In the case of fabricating multilayer boards, the end price per PCB naturally increases on a layer-by-layer basis. For example, adding each 1-2 extra layers causes a 30-40% price increase consequently. Therefore, 10-12 layer PCB may cause three times more than 1 or 2 layer PCB.
It is explained by the increase in production steps involved in the lamination process and the complexity of the design creation.
4. The thickness of the PCB
As a rule of the thumb, thicker boards are more expensive to produce. They are more difficult to laminate and require way more material. It is not like 3 mm PCB is going to cost three times more than 1 mm PCB, but close to it.
But the important consideration here are the dimensions, components mounted, design, etc. Sometimes, thin PCBs with improper design are more costly to produce than thick but simple boards.
5. Minimum trace and space
Traces in any PCB design is an essential aspect. There is a correlation between trace width and carrying capacity. Besides, cross-sections correlate with the thicknesses of the copper coating. The latter is impacted by components mounted, vias, pads, etc.
The big idea here is to prevent a trace from carrying more capacity than it is intended for. It will cause excessive cross-sectional areas. So, there is a need to enlarge the trace width that reduces the available space. Not sticking to trace and space rules lead to either poor PCB quality or extra expenses in compensating for the problem.
6. Type of finish
Unsurprisingly, the method of PCB finish impacts the cost significantly. Your options here are HASL, LFHASL, OSP, Immersion Silver, Immersion Tin, ENIG, ENEEPIG, and others. Some of them are just generally more expensive to apply than others. Still, the end cost heavily depends on your supplier’s capacities.
7. Batch size
That’s something that is difficult to state for sure, but larger batch sizes typically result in quantity discounts. But it heavily depends on the load of a supplier, its capacities, and other factors. The best approach here is to ask a supplier directly what batch sizes are optimal and balance productivity, quantity, and turnaround time.
8. Packaging
Shipping such fragile electronics as PCBs can be fairly expensive. Some of them must be packed with components mounted; others require electrostatic bags. Besides primary, there is also secondary packaging. So, such expenditures can be quite notable.
9. Test requirements
In the case of custom PCB fabrication, you definitely need your boards to undergo extra rounds of testing. Intricate designs and extra requirements add to the number of checks to run, which heavily impact end costs.
10. Custom specifications
These are typically contoured edges, side-plating, and extremely tight solder mask clearance. In case of requesting any of those, the complexity of a design will rise drastically. It also concerns unique other unique design requests such as an unusual hole or vias diameters, etc.
11. Shipping
Delivery of large batches of fragile components typically results in higher costs. These even do not directly depend on the distance but rather on vehicles used and the number of delivery requests.