PCB Cost Drivers
Customers and buyers who are new to the printed circuit board (PCB) market may be confused as to how the fabricator prices a particular job. We’ll debunk the factors fabricators use to determine price in this blog, giving you the tools you need to effectively plan and price your next PCB project.
PCB pricing is influenced by a number of PCB Cost Drivers. Every PCB manufacturer’s overhead expenses will be comparable, including the need for a facility, equipment, labour, and raw material costs. Chemical processes and waste water treatment systems are examples of additional overhead expenses that affect PCB pricing since they require special (i.e. expensive) approvals, permits, zoning, and other requirements. Raw materials are expensive in any manufacturing business, but they are specifically used in the printed circuit board fabrication process (examples include gold, silver, copper, nickel, lead, fiberglass, epoxy resin, and a variety of chemicals).
Aside from manufacturing overhead and raw material costs, there are both primary (board size, quantity, layer count, lead time, etc.) and secondary (tooling, finish type, drill type, lamination process, etc.) cost considerations when a fabricator sets out to calculate PCB Cost Drivers. We’ll start by tackling the primary cost considerations:
PCB Determining Cost Factors
Board Size
One of the raw materials required to make a printed circuit board is a panel. When determining cost/price, the size of a printed circuit board, or how much “real estate” it takes up on a panel, will be a key consideration. Although it appears to be straightforward, things can quickly become complicated. For example, depending on the dimensions, it is feasible to have a board that takes up less space but costs more. The reason for this is that one dimension may fit the panel better than the other depending on the total size of the panel used to manufacture the board.
Quantity
Quantity is crucial because many manufacturers will have a minimum cost for an order. For example, a project may only require 10 pieces, but the minimum order quantity may require 20. The cost per board will fall as the quantity increases, until the least manufacturing cost is reached.
Some manufacturers will give you a bigger discount if you buy in bulk, but you’ll get smaller quantities over time. For example, if a 500-piece purchase is placed, 100 pieces will be supplied each month until the order is completed. The manufacturer gains production efficiency by making all 500 pieces at once, while the customer achieves cash flow efficiency by only paying for the product that has been delivered.
Lead Time
“Time is Money” for PCB manufacturers. The more quickly a project must be manufactured, the more it will cost – often by 30 to 200 percent more. There are real costs associated with prioritising new projects above existing work in progress for a company, and some of those expenses are reflected in pricing.
Layer Count
The number of layers has a considerable impact on the cost. Manufacturing costs for single-sided and double-sided PCBs are nearly the same. Multi-layer PCBs, on the other hand, add to the materials and manufacturing expenses. Moving from a 2 layer PCB to a 4 layer PCB will typically twice the cost. Adding more layers to a multi-layer project will increase the cost, but the price increase will be less obvious. Moving from 4 layers to 6 layers, for example, could cost 50% more than moving from 2 layers to 4 levels, which would cost 100% more.
Drill Size and Count
Another factor to think about is the smallest hole size that has to be drilled and the total number of holes that need to be drilled. When the hole size is less than 0.015′′, the PCB cost can rise by 5% to 10%. A significant number of holes can drive up the price by a similar amount. This is because the manufacturing process must be altered for smaller hole sizes and higher hole counts, reducing the number of panels that can be drilled at once.
Material Type and Thickness
There are several other types of materials that can be used to make a PCB, the most popular of which is FR-4. Fiberglass and other materials are woven together with an epoxy resin to create FR-4, which has fire-resistant qualities. Temperature rises Other material types that could be used to make high copper weight, hybrid capable PCBs or more include FR-4, Polyimide, Hybrid Capable, High Copper Weight, and Flex. 0.062′′ is the most typical material thickness. Choosing different types of materials and thicknesses can have a big impact on cost.
Space
Many of today’s projects require the use of very small components. The spacing between copper features on a board must be reduced to allow this. It’s critical to leave as much room as possible on the board to keep prices down. Costs may rise by 5% to 10% if the trace/space is less than 0.006″.
These are the most important factors to consider when a fabricator prepares a price quotation for a customer, although there are many more. Understanding the assumptions and calculations behind a quoted price can help you design smarter, more cost-effective printed circuit boards. We’ll now go through some of the secondary cost-determining factors:
Secondary Cost Determining Factors
Tooling and Test Charges
Tooling costs could include CAM time, film costs, etc. A variety of tests can be carried out during the manufacturing of a printed circuit board. The most frequent is an electrical test, which involves performing a basic open and shorts test on the PCB to ensure that it is electrically sound. TDR for Impedance Testing, Ionic Testing, and other tests are normally performed at the request of the customer. The costs of these things vary hugely depending on the manufacturer.
Finish Type
The most popular finish type is still Hot Air Solder Leveled (HASL), which is a lead finish. There are a variety of additional finishes available, including silver finishes, gold finishes (ENIG, body gold, gold fingers, etc), and more. These non-standard finishes can increase the cost of a project by 10% to 20% or more.
Drill Type
If significantly smaller holes – known as microvias – are desired, a laser drill process is required. The use of a laser drill can significantly increase the overall cost of the process. Blind or buried vias, are another cost aspect to consider. Each additional drill step can increase the entire board cost by as much as 20% or more.
Lamination Process
Processing a multi-layer printed circuit board that requires a non-standard process can increase costs. A process that involves laminating FR4 with a different material type, such as polyimide, is an example.
Specification Standards
Final printed circuit board inspection and quality processes are controlled by the IPC Class 2 standard. Class 3 is an upgrade from Class 2 that requires additional procedures to the manufacturing process, such as coupons and cross-sections. Customers who demand a higher level of quality assurance may opt to seek a Class 3 procedure, but they should expect a 15 % to 20% increase in project costs.
Via Fill
A PCB’s vias are usually not completely filled. Copper plating and a finish will be applied to the holes, but they will not be completely filled. Vias, on the other hand, can be filled with either non-conductive or conductive material if necessary. The cost of the PCB will add 10% or more by this process.
Fabrication
Additional fabrication costs will be incurred if the finished board requires additional fabrication. Counterbores, countersinks, complex routing, controlled depth drilling, etc are examples of these. The cost of these services varies greatly depending on what is required.
These are secondary factors that a fabricator considers when creating a price quotation for a customer.
Cerra Systems Printed Circuit Board Fabrication capabilities support high-frequency PCB, High-temperature Boards, Thick PCB, ultra-thin PCB, heavy copper PCB, Metal Core PCB, HDI boards with Blind Vias, Buried Vias, Micro Vias, Embedded passives, bonded heat sink, Impedance Control, Depth control drilling, Back drilling, Edge Plated PCB, Bump Pads, cavity with ledge, Via on pad and stacked micro-Via technology.
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