At present, the main products of SMT patch are: lead-free soldering process, lead soldering process and red glue soldering process. And its point calculation method is very similar, but many users don’t know much about the calculation of SMT patch points and how to calculate the cost.
Some companies calculate one pad as one point, but there are two solder joints as one point. This article takes PAD calculation as an example. All you have to do is to calculate the number of pads on the PCB, but when you encounter some special components, such as inductors, large capacitors, integrated circuits, etc., you need to calculate the rated power. The specific experience is as follows: For example, the inductance can be counted as 10 points, and the IC can be discounted according to the number of pins (for example, a 40-pin IC is counted as 20 points). According to the above method, the total number of solder joints of the entire PCB board can be easily calculated.
Unit price of solder joints:
Currently on the market, the unit price of solder joints varies from 0.008 to 0.03 yuan per solder joint. This depends on the following conditions:
1. The unit price is based on the process:
A Solder paste has lead SMT chip processing and the price is relatively cheap.
B Solder paste lead-free SMT chip processing costs are relatively high.
C Red glue environmentally friendly SMT chip processing cost is relatively low.
D solder paste red glue dual process SMT chip processing cost is high, the process is relatively troublesome.
2. According to the number of orders:
A Common SMT patch proofing processing 3-20 pieces, there will be an engineering fee, and it will not be calculated by multiplying the unit price by the number of points.
B Small batch SMT patch processing produces less than 1,000 pieces, and a start-up fee + points multiplied by the unit price will be charged.
C Batch SMT chip processing is calculated by multiplying the calculation points by the unit price.
3. Press the difficulty of the board
A Single and side split Single-sided SMT patch processing is relatively fast, and double-sided SMT patch processing needs to be transferred twice, and the cost is higher.
B precision points More precise SMT chip processing. If there is a BGA high-density IC. The solder paste for the board will be expensive.
C Density of SMD components There are many points in the same size PCB board. The efficiency will be high, because the shorter the stroke of the coordinates when the placement machine is working, the faster the SMT wafer processing will be.
4. Start-up fee: the processing fee for a single batch of less than 1,000 yuan is a small batch processing order. After the small batch SMT placement processing order is calculated according to the number of points, the type of the kanban sub-components, the time for debugging the placement machine, and the difficulty of making the first piece will be charged with a start-up fee ranging from 400 to 2,000 yuan.
5. Proofing fee: SMT patch processing order is an SMT patch proofing order with less than 100 pieces. The difficulty of the board, the time of the program, the time of on-board transfer are different, and the charge is 800 yuan to 3,000 yuan. And other engineering costs.
6. Steel mesh fee: According to the size of the PCB board, open different types of steel mesh. According to the precision of the chips on the PCBA board, choose to turn on the electro-polished steel mesh or the ordinary steel mesh. The cost of different types of stencils ranges from 120 to 350. Of course, customers can also provide their own steel mesh.