PCBA processing plant: quality control of SMT chip processing

The product processing quality determines the product life cycle, and also determines whether pcb electronICs manufacturers can survive in the highly competitive electronic processing environment. Since we accepted the processing projects of customers, we have taken the most serious attitude and strictly followed the international standards or the production standards of customers to produce, so as to provide you with the most perfect quality. ".? 1、 Material inspection Material inspection is IQC. Material inspection is the first step to ensure production quality and the basis for smooth SMT chip processing. Next, we will introduce the main inspection points for you in detail 1. Incoming inspection and inspection of electronIC components

The processing quality of products determines the service life of products, and also determines whether electronic manufacturers can survive in the highly competitive electronic processing environment. Since we accepted the processing projects from customers, we have taken the most serious attitude and strictly followed the international standards or customer's production standards to produce, only to provide you with the most perfect quality.

1、 Material inspection

Material inspection is calLED IQC. The inspection of materials is the first step to ensure the production quality and the basis for smooth SMT chip processing. Next, we will introduce the main inspection points for you in detail

1. Incoming inspection

Check whether the specification, generation, model, withstand voltage value, appearance and size of electronic components and other materials are consistent with the BOM list provided by the customer, to ensure that the materials meet customer requirements. There is also chip inspection. The size, spacing, package and pin of the chip need to be inspected by QC

2. Tinning inspection

Tin the IC pin and plug-in component materials to check whether they are oxidized and whether the materials eat tin.

3. PCB board inspection

The quality of PCB board determines the quality of finished PCB, otherwise false soldering, false soldering and floating will occur. Therefore, it is necessary to check whether the PCB board is deformed, flying wires, scratches, damaged lines and flat.

4. PCB board tin eating inspection

The wetness affects the tin eating rate of PCB, and poor tin eating rate will lead to insufficient solder joints.

5. Through hole position inspection

The size of the through-hole location diameter is determined by the size of the components. If it is too SMAll or too large, the components cannot be inserted or fall off.

2、 Solder Paste Inspection

Solder paste is sourced from international brand Qianzhu Solder Paste, which is supplied by special suppliers. Solder pastes shall be used according to the "first in, first out" standard, that is, those purchased first shall be used first. The storage temperature of solder paste is generally between 0 ℃ and 10 ℃, plus or minus 1 ℃. Solder paste needs to be unfrozen before use, generally about 4h at room temperature. Use needs to be identified, and the rest needs to be recycled, but it needs to be recycled twice to the supplier for treatment to avoid environmental pollution. Before using the solder paste, use an automatic mixer to stir it for 5min to prevent air from entering the solder paste and generating bubbles.

3、 Steel mesh and scraper control

The size of steel mesh is generally 37cm * 47cm, and the tension is 50~60MP. Tensioners are generally used for tension testing. The storage temperature of the steel mesh should be better controlled at 25 ℃. The edge of the steel mesh is a rubber edge. If the temperature is too high, it will become brittle, causing damage to the steel mesh. The scraper shall be operated at an angle of 45 degrees, and the ordinary steel mesh scraper shall be scrapped after 20000 times of use. The thickness of the steel mesh will become smaller, which will affect the tension of the steel mesh and lead to incomplete tin scraping.

4、 Placement machine adjustment and first QC

Adjust the coordinates of the automatic placement machine according to the BOM, template, ECN file and other coordinate files provided by the customer to ensure accurate measurement and high placement accuracy. This is the QC inspection of the first piece mounting. The QC personnel check whether there is missing pasting, flying pasting, and whether the mounting direction and mounting are accurate. Batch production can only be carried out after confirmation.

5、 Reflow welding control and second QC

The reflow temperature setting requires different parameter settings according to the PCB material, such as cardboard, 2-layer board

PCB manufacturers, PCB designers and PCBA manufacturers will explain the quality control of SMT chip processing.