PCB News - PCB circuit board production cost composition

PCB circuit board production cost composition

When purchasing PCBs, PCB buyers often don't know how the price of PCBs is composed! It is not easy to inquire and purchase, here is a brief introduction to the basic components of the price of the circuit board! Of course, according to the craftsmanship and materials of each PCB production factory, the price of each factory is also different. In addition, the factors of the circuit board itself also determine that the focus of its cost calculation is not the same, there are simple (length * width * square unit price), and some are complex (calculated according to process requirements\quality requirements, etc.), and specific analysis is required. !

A. As far as the plate is concerned: the main factors affecting the price are as follows:

1. Sheet material: FR-4, CEM-3, this is our common double-sided and multi-layer board, and its price is also related to the thickness of the board and the thickness of the copper foil in the middle of the board, and FR-I, CEM-1 These are our common single-sided board materials, and the price of this material is also very different from the above double-sided, multi-layer boards.

2. The thickness of the plate. The thickness of the plate is 0.4, 0.6, 0.8, 1.0, 1.2, 1.5, 1.6, 2.0, 2.4, 3.0, 3.4. The thickness and price of our conventional plates are not very different.

3, the thickness of copper foil will also affect the price, the thickness of copper foil is generally divided into: 18 (0.5OZ), 35 (1OZ), 70 (2OZ), 105 (3OZ), 140 (4OZ) and so on. (oz is the abbreviation of the symbol ounce, Chinese called "ounce" (Hong Kong translated as ounce) is an imperial unit of measurement, when used as a unit of weight, it is also called English liang. 1oz=28.35g (gram))

4. Suppliers of raw materials, common and commonly used ones are: Shengyi\Jiantao\International, etc.

For drilling, the price effect is not as big as that of the plate, but if the hole is too many and too small, the price will have to be calculated separately. If the hole diameter is less than 0.1, the price will be higher.

B. Process cost:

1. It depends on the circuit on the PCB. If the wire density is thin (below 4/4mm), the price will be calculated separately.

2. There is a BGA on the board, and the cost will rise relatively. Some PCB manufacturers use BGA for another.

3. It depends on the surface treatment process. Our common ones are: spray lead tin (hot air leveling), OSP (environmental protection board), spray pure tin, tin, silver, gold, etc. Of course, the surface technology is different. The price will also be different.

4. It also depends on the process standard; what we commonly use is: IPC2, but there are customer requirements that will be higher. (such as Japanese) Our common ones are: IPC2, IPC3, enterprise standards, military standards, etc., of course, the higher the standard, The price will be higher.

C. Finally, it depends on the shape of the PCB. For the shape, we usually use milling shapes, but some boards have very complicated shapes. We only need to open the mold and use the punch, so there will be a set of mold costs.

To sum up, the basic factors affecting the price of PCB boards are as follows:

1. Board size

2. Number of layers

3. Surface treatment

4. Production quantity

5. Plate

There are other factors that have some influence on the price

1. The line spacing between lines is too small

2. Many holes

3. The minimum aperture is too small

4. Mould

5. Tolerance is too tight

6. Plate thickness aperture ratio

6. Special requirements (the finished product is too thin or too thick, thick copper plating, non-repeatable barcode, etc...)

The main advantage of SMOBC board is that it solves the short-circuit phenomenon of solder bridging between thin lines. At the same time, due to the constant ratio of lead to tin, it has better solderability and storage properties than hot melt board.

There are many methods for manufacturing SMOBC boards, including the SMOBC process of standard pattern electroplating subtraction and lead-tin stripping; the subtractive pattern electroplating SMOBC process of using tin plating or immersion tin instead of electroplating of lead-tin; the plugging or masking hole SMOBC process ; Additive method SMOBC technology and so on. The following mainly introduces the SMOBC process and the plugging method SMOBC process flow of the pattern electroplating method and then the lead and tin stripping.

The SMOBC process of pattern electroplating followed by lead and tin stripping is similar to the pattern electroplating process. Changes only after etching.

Double-sided copper-clad board --> According to the pattern electroplating process to the etching process --> lead and tin removal --> inspection --> cleaning --> solder mask pattern --> plug nickel plating and gold plating --> plug sticking tape --> Hot air leveling --> Cleaning --> Screen printing marking symbols --> Shape processing --> Washing and drying --> Finished product inspection --> Packaging --> Finished product.

The main process flow of the plugging method is as follows:

Double-sided foil-clad laminate --> drilling --> electroless copper plating --> electroplating copper on the whole board --> plugging holes --> screen printing imaging (positive image) --> etching --> removing screen printing materials, Removal of plugging material --> Cleaning --> Solder mask pattern --> Nickel-plated and gold-plated plug --> Plug tape --> Hot air leveling --> The following procedures are the same as the above to the finished product.

The process steps of this process are relatively simple, and the key is to plug the holes and clean the ink that plugs the holes.

In the hole plugging process, if the hole plugging ink and screen printing imaging are not used, a special masking dry film is used to cover the hole, and then exposed to make a positive image, this is the masking hole process. Compared with the hole blocking method, it no longer has the problem of cleaning the ink in the hole, but it has higher requirements for masking the dry film.

The basis of the SMOBC process is to first produce a bare copper hole metallized double-sided board, and then apply a hot air leveling process.