PCBA Tech - SMT incoming inspection and PCBA accounting quotation

SMT patch processing inspection of incoming materials

Inspection before SMT chip processing is the primary condition to ensure the quality of the chip. The quality of electronic components, printed circuit boards, and smt chip materials directly affect the quality of the PCB board. Therefore, the electrical performance parameters of electronic components and the solderability of soldering tips and pins, the productivity design of printed circuit boards and the solderability of pads, solder paste, patch glue, rod-shaped solder, flux, cleaning The quality of smt patch materials such as agents must have strict incoming inspection and management systems. The quality problems of electronic components, printed circuit boards, and smt patch materials are difficult or even impossible to solve in the subsequent process.

1. Inspection of smt chip electronic components:

The main inspection items of electronic components include: solderability, pin coplanarity and usability, which should be sampled by the inspection department. For testing the solderability of electronic components, stainless steel tweezers can hold the electronic component body and immerse it in a tin pot at 235±5 degree Celsius or 230±5 degree Celsius, and take it out at 2±0.2s or 3±0.5s. Check the soldering end of the solder under a 20 times microscope, and it is required that more than 90% of the soldering end of the electronic component is soldered.

The patch processing workshop can do the following visual inspections:

1. Visually or with a magnifying glass, check whether the solder ends or pin surfaces of electronic components are oxidized or have no contaminants.

2. The nominal value, specification, model, accuracy, and external dimensions of electronic components should be consistent with the product process requirements.

3. The pins of SOT and SOIC cannot be deformed. For multi-wire QFP devices with a wire spacing of less than 0.65mm, the pin coplanarity should be less than 0.1mm (which can be optically detected by the placement machine).

4. For products that require cleaning, the marks of electronic components will not fall off after cleaning, and will not affect the performance and reliability of electronic components (visual inspection after cleaning).

PCBA processing accounting quotation time required

Under normal circumstances, people say how long it will take to process the latest price of PCBA, which starts from which links are included in PCBA production. Perhaps everyone knows that PCBA is a general term for PCB welding in China. It includes three major parts (PCB circuit board, SMT patch, electronic component welding), then the latest price of PCBA must be determined by these three parts.

1. PCB board: the board-making materials and board-making instructions files required for the latest price of PCB. If the information is complete, sort out all the information. How much is the special process to be charged separately, plus other miscellaneous fees, basically a complete set of prices can be quoted within 2 hours. If there are still many newest prices waiting ahead, it's a different matter.

2. SMT chip processing section: This module is mainly an accounting of processing fees. Usually the PCBA factory counts money according to the points, some are one point by one point, and some are one point for each foot. This is the biggest trick. There are at least 2 feet for each piece. If one piece is counted as one point, it may be a single point price. It will be higher than the price of one point per foot. After all, there are few points, and no one can buy and sell at a loss. So don’t look at a point that’s expensive and don’t evaluate it. The evaluation of this piece can actually be done within one hour.

3. Electronic components module: electronic components include conventional resistance-capacitance and special devices. The current market for conventional components is transparent, and it is easier to evaluate the price, but some special BGA/IC will be more troublesome. Strict approval process, long customs clearance time, and unstable prices. So the latest price cycle is usually 3 to 4 days.

Basically, after the above decomposition, everyone will find that the latest price of PCBA takes a few working days. Unless it is a company with its own stock materials that can evaluate it in a very short time, the others may only be PCB and SMT stickers. The film is faster. In some cases, for example, there are many orders and the latest price list is very tight. It must be the one who reports first. After all, customers are treated equally.