At present, the main products of SMT are: lead-free soldering process, lead soldering process and red glue soldering process. Moreover, 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 soldering points as one point. Take PAD calculation as an example. All you have to do is 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 (such as 40-pin IC, counting as 20 points). According to the above method, the total number of solder joints of the whole PCB can be calculated conveniently.
Unit price of solder joint:
At present, the unit price of solder joints varies from 0.008 to 0.03 yuan/solder joint price, which depends on the following conditions:
1. Unit price according to process:
A solder paste with lead SMT patch processing price is relatively cheap.
The processing cost of B solder paste lead-free SMT patch is relatively high.
The processing cost of C-rubber environmental protection SMT patch is relatively low.
D solder paste and red glue dual-process SMT patch has high processing cost and relatively troublesome process.
2. By order quantity:
A common SMT chip proofing processing 3-20 pieces, will charge the engineering fee, not according to the number of points multiplied by the unit price.
B small batch SMT chip processing and production of less than 1000 chips, will charge the startup fee+points multiplied by the unit price.
C SMT patch processing in batches, calculated by multiplying the number of points by the unit price.
3. According to the difficulty of the board
A single-sided, single-sided SMT patch processing is relatively fast, and double-sided SMT patch processing needs to turn twice, so the cost is high.
B precision points to more precise SMT chip processing. If you have BGA high density IC, the solder paste for the board will be expensive.
The density of C chip components is divided into many points in the same size PCB. The efficiency will be high, because when the mounter works, the coordinate stroke is shorter, and the SMT chip processing will be faster.
4. Start-up fee: If the processing fee of a single batch is less than 1000 yuan, it is a small batch processing order. After the small batch SMT chip processing order is calculated according to the number of points, it will depend on the type of board components, the time for debugging the chip mounter, and the difficulty of making the first piece. An additional startup fee ranging from 400 to 2000 yuan will be charged.
5. Proofing Fee: For SMT chip processing order, a proofing order for SMT chip with less than 100 chips, the difficulty degree of the board, the time to do the program and the time to change the line on the computer are different, and the engineering fee ranging from 800 yuan to 3,000 yuan will be charged.
6. Steel mesh fee: according to the size of PCB, open different types of steel mesh. According to the precision of PCBA chip on board, choose electropolished steel mesh or ordinary steel mesh. The cost of steel mesh for different types of steel mesh is about 120~350. Of course, customers can also provide their own steel mesh.