PCB board cost sometimes is confused for many customers, buyers and someone new in printed circuit board industry due to its diversity in specification and production process. This article is to inform some key factors that determine the price of a board, which help you to better plan your design and clear the cost details.
PCB cost is composed of many elements. Each element many bring to difference in final PCB offer. The first is every PCB factory will have expense in house, equipment, labor and other operation cost as all other companies. This part cost may differ a lot for PCB manufacturers from different area. Take this part of basic cost aside, today we mainly discuss the factors of a printed circuit board specification and process.
a. PCB material and thickness
There are many types base material types used for PCB production. Take the most common used FR-4, there are many manufactures (such as SY, KB, GJ, ITEQ, Rogers…) provide different grade CCL with different thickness from 0.2mm to 3.0mm or more… It will have significant impact on price to choose different material types and thicknesses.
b. Copper thickness
Common copper thickness used is 18um (1/2 oz), 35um (1oz), 70um (2 oz), 105um (3 oz), 140um (4 oz) etc.. Usually the heavier of copper, the expensive of PCB cost. Heavy copper require bigger line width and space in design too.
b. Surface finishing / treatment
For most of PCB manufacturers, there are OSP, HASL, Lead-free HASL, Immersion gold /tin/silver, Plating gold and other treatment could chose to customers. But different requirement in treatment will also cause the cost difference. Take the most used HASL and Immersion Gold (ENIG) for example, the cost of ENIG is much higher than HASL, and the bigger area need to deal with, the higher cost need to pay.
c. Drilling/ Line/Production process
- For drilling, quantity, types and size will have impact on production cost. Usually for normal PCB factory, when the hole size is smaller than 0.3mm, there will be around 5% cost increased. And big quantity of hole will also some cost increased due to production efficiency reduced (time increased).
- And another factor is line width and space, the production cost will different for conductor width /space 4mil/4mil, considering production difficulty, reject rate and so on.
- Other factors require special process like half plated hole, blind & buried via, tented via, press fit holes, microvias, carbon oil and so on will also take part of cost.
d. Quantity / Lead time
- Quantity is an important factor for PCB cost. Many PCB manufacturers will have a minimum cost for an order because of many of work included is similar for 1pcs and 1Kpcs. So usually the quantity increase the unit cost will decrease.
- Lead time will also have some impact on PCB offer, especially for some quick turnaround board. Usually faster delivery means more will cost. To achieve a fast delivery, it will also require buyer provide complete PCB file include Gerber, specification, quantity, stack up and so on.
e. Fly test / E-tester/ Mould
Generally for sample and prototype (usually smaller than 3 square meters depends on boards), PCB supplier will suggest to using flying probe test to save cost. And mass production PCB manufacturer will require building e-tester. E-tester is non-recurring cost with no version updated, which is economical for repeat order.
Mould is usually used for mass production, and small usually use milling.
f.Quality required / Payment
For PCB quality standard, there is IPC2, IPC3, Military standard and so on. Simply speaking, the higher standard requires, the higher cost need.
Payment sometimes will also considered in the PCB offer for many PCB manufacturers.