What are the cost components of PCB

2020-06-04

NO.	Composition of general category	Specific items	Cost impact point	Proportion of total cost	Cost difference
1	Direct material	Base material + Prepreg of multilayer	Brand	30%	Big difference between famous brands and other brands
			Texture of material		The cost difference between FR-4, FR-1 and CEM-1 was 2.4 times The price difference of high frequency PCB material is very big
			Board thickness		It is divided into 1.60/1.20/1.0/0.8mm, and the difference between different grades is 10-20 yuan for each large sheet of material of the same brand
			Copper thickness		35um for inner layer and 17.5um for outer layer, cost increases 50 yuan for every 1 oz increase of copper thickness (single layer)
			TG temperature		It refers to the glass conversion temperature, which is divided into high, medium and ordinary TG. The difference between different grades is 20-50 yuan for each sheet of material of the same brand
		Printing ink	Brand		Big difference between famous brands and miscellaneous brands
			Colour		Generally, green oil is used, which refers to soldermask and plug hole. If black oil or blue oil plug hole is used, the cost will rise by about 5%, because the waste rate will be increased in PCB production
			Category (dry film / wet film)		Such as liquid photosensitive ink, the category has little effect on the price, and the difference between dry film and wet film is 10%
		Liquid medicine (electroplating and other processes)	Brand and grade		Big difference between famous brands and miscellaneous brands
		Copper ball, tin ball, surface treated metal	Brand and thickness		There are big differences between well-known brands and miscellaneous brands. In addition, there are big differences in the cost of IP card board (Gold finger board) with different thickness of gold, and the cost of different surface treatment processes. Among the cost of immersion gold/Immersion Au, lead-free HASL, lead tin and OSP, OSP is the lowest, and the flatness is the best
		Processing fixture	Forming mould		Single panel is divided into punching die and CNC die, the total cost is 2000-5000 yuan.Every time the hardware is upgraded, the punching die will be scrapped if it can't continue to be used. For conventional double-sided or multi-layer boards, some slotted holes will be punched with the die. The cost of using CNC to make them is higher. Generally speaking, CNC is mostly used
			E-Test fixture, film, screen, soldermask fixture		According to the complexity, about 2000-3000 yuan
			Screen, Drill nozzle, etc		About 500-1000 yuan, each change will involve the change of processing fixture
2	Direct labor	Wages			Labor costs vary from region to region, and labor costs in mainland factories are cheaper
3	Manufacturing expenses	Manufacturability design	Utilization rate of material	50%	The key to improve the utilization rate of sheet metal is, the area of each single board can be reduced to more unit boards arranged on each large sheet of the supplier. The cost will be reduced by 5-10 yuan / m2 with the utilization rate increased by 10%
			Drill hole		The more holes we design, the higher the cost of drilling, and the higher the cost of hole treatment (copper plating is also required in the hole). For every 10000 ground holes reduced, the cost will be reduced by 8 yuan per SQM.
			Minimum line width and line spacing		If the line width is less than or equal to 4 / 4mil, the cost will rise (for example, the smaller the BGA pad, the higher the cost)
			Minimum hole size		If the minimum hole diameter is less than 0.30mm (not included), the cost will rise (in which, too many 0.3mm vias will affect the manufacturing cost)
			Plating thickness diameter ratio > 6:1		Plating thickness / minimum hole diameter ratio, i.e. the hole is small but the board is thick, the plating difficulty is increased, the rejection rate of through hole defect is increased, and the cost of more than 6:1 will rise
			Copper laying area of PCB		The more copper laying area of PCB, the higher material consumption and water and electricity cost. It is also not conducive to heat dissipation after process reflux (grid copper laying can but also has disadvantages)
			Differential impedance and characteristic impedance		Increase by 5% - 10% depending on the difficulty
			Other processes with high difficulty		Cost will rise
			Surface treatment process		Choose the lowest OSP cost
			Plug via hole		Plug hole, usually the cost for each squaremeter is about 15 yuan
			Selection of dry film and wet film		The cost of dry film is about 15 yuan higher than that of wet film
			Selection of forming process		The cost of single board small batch CNC process is twice higher than that of batch die stamping, and the die stamping of double-sided board is at least 20 yuan higher than that of CNC per SQM.
		Process capability	Hardware and software cost		The cost of different hardware and software investment is different. For example, for soldermask alignment, some suppliers are manual alignment, some are CNC alignment. The cost of a CNC alignment machine is up to 2 million yuan. The depreciation cost of the equipment causes the cost to rise
		One time qualification rate and scrap rate	Single x-out caused by panel number		The more pieces of each board are assembled, for example, 8 pieces, there may be 2 pcs of broken boards (X-out board), but the other 6 pcs are good boards. The more pieces are designed, in fact, if the X-out boards exceed the customer's proportion requirements, they will be scrapped, and the good boards in X-out board will become broken boards, causing the cost to rise
		One time qualification rate and scrap rate	Quality failure cost		High scrap rate and low one-time qualification rate are related to the level and ability of the supplier
4	Period expenses	Management expenses			Varies by company
		Operating expenses			Varies by company
		Financial expenses			Varies by company
5	Other expenses	Schedule cost	Prototype making		You need to pay for the prototype board and find the fast PCB prototype company.The factory will arrange orders according to the plan, and if you want to speed up the progress, you need to pay an expedited fee.