Analysis of SMT chip processing points and cost calculation method

At present, the main products are: lead-free PCB welding process, lead welding process and red glue welding process. The point calculation method is also very similar, but many users do not know much about SMT patch point calculation and cost calculation.

Some companies calculate a PCB pad as a point, but have two solder joints as a point. This paper takes PAD calculation as an example. All you have to do is calculate the number of pads on the PCB. However, when you encounter some special components, such as inductors, large capacitors, integrated circuits, etc., you need to calculate the rated power. Specific experience is as follows: For example, inductance can be counted as 10 points, and IC can be discounted according to the number of pins (such as 40 pin IC, counted as 20 points). According to the above method, the total number of solder joints of the entire PCB can be easily calculated.

Unit price of solder joint:

At present, the unit price of PCB solder joints varies from 0.008 to 0.03 yuan per solder joint, depending on the following conditions:

1. Unit price according to process:

A Solder paste with lead SMT chip processing price is relatively cheap.

The processing cost of lead-free SMT pastes of solder paste B is relatively high.

The processing cost of C red glue environmental protection SMT patch is relatively low.

D solder paste red glue dual process SMT patch processing cost is high, the process is relatively troublesome.

SMT patch

2. Quantity by order:

A For 3-20 pieces of common SMT chip proofing processing, the engineering fee will be charged, and it will not be calculated by multiplying the points by the unit price.

B For small batch SMT chip processing and production of less than 1000 pieces, the startup fee+points multiplied by the unit price will be charged.

C Batch SMT chip processing, calculated by multiplying the number of points by the unit price.

3. According to the difficulty of the board

A Single sided SMT patch processing is relatively fast, while double-sided SMT patch processing needs to be switched to twice, which is costly.

B Precision SMT chip processing. Solder pastes for BGA high-density IC boards will be expensive.

C The density of SMD components is divided into many points in PCB boards of the same size. The efficiency will be high, because the travel of the coordinates is short when the SMT mounter is working, the faster the SMT chip processing will be.

4. Start up fee: small batch processing orders with single batch and single processing fee less than 1000 yuan. For small batch SMT chip processing orders, after counting the number of points, depending on the type of board sub components and the time of debugging the chip mounter, a start-up fee ranging from 400 to 2000 yuan will be charged depending on the difficulty of making the first piece.

5. Proofing fee: SMT chip processing orders with less than 100 pieces are SMT chip proofing orders. The difficulty of the board, the time to do the program, and the time to go on the machine and transfer to the line are different, so the engineering fees ranging from 800 yuan to 3000 yuan will be charged.

6. Steel mesh fee: open different models of steel mesh according to the size of PCB. According to the precision of the chip on the PCBA board, choose to turn on electric polishing steel mesh or ordinary steel mesh. The cost of different types of steel mesh is about 120~350.