PCB Tech - PCBA production processing and quality control focus

The links and production processes involved in PCBA processing are more complicated, and problems in any link may eventually cause a chain reaction, so quality control is very important. The following introduces the production and processing quality control of PCBA manufacturers, and what are the key links of quality control.

1. Brief introduction of PCBA manufacturer's production and processing quality control

1. Process analysis

It needs attention from the beginning of receiving the processing order. At the beginning, the process analysis was carried out according to the PCBGerber file and the manufacturability report was provided.

2. Incoming inspection

If you want to produce good quality PCBA, you must first control the quality from the raw materials. The quality inspection of components needs to be paid attention to, especially the orders of PCBA foundry materials, which need to be paid attention to from the component procurement channels., Procurement of components from large traders, distributors and original factories to fully ensure that there will be no problems with the quality of components. Refurbished components and counterfeit components have a great impact on the quality of products. Especially PCBA foundry orders need to pay more attention. Generally, PCBA manufacturers have after-sales commitments for such orders. Problems with components are not only Increasing costs for ourselves is also causing trouble to customers. The PCB needs to check the temperature of the reflow oven, whether the fly-line vias are blocked or leaking, whether the board surface is bent, etc. The IC needs to check whether the screen printing is exactly the same as the BOM, and store it at constant temperature and humidity. Other commonly used materials need to be checked for screen printing, appearance, power-on measurement, etc.

3. SMT patch processing

Solder paste printing and reflow oven temperature control system are the key points of assembly, and laser stencils with higher quality requirements and better processing requirements are required. Strict implementation of the AOI test can greatly reduce the defects caused by human factors.

4. Plug-in

In the plug-in process, the mold design for wave soldering is the key.

5. Quiz

For orders with test requirements, PCBA manufacturers' main test contents include ICT (circuit test), FCT (functional test), burn test (aging test), temperature and humidity test, drop test, etc.

PCBA processing

Second, the key links of quality control in PCBA processing

1. SMT patch processing

The systematic quality control details of solder paste printing and reflow soldering temperature control in the SMT chip processing production process can be described as a key node in the entire PCBA processing. High-precision printing requires laser stencils to meet high-quality requirements. The factor of temperature control accuracy of reflow soldering is of great significance to the wetting of solder paste and the firmness of soldering. In actual processing, it can be adjusted according to SOP operation, thereby reducing PCBA processing defects during SMT processing. Performing AOI testing strictly in accordance with the requirements in the patch processing link can also achieve good quality control results.

2. DIP plug-in

DIP plug-ins are generally the back end of the entire PCBA processing process. Some traditional plug-in components that are inconvenient to convert into chip components will be inserted into the furnace in this link, and the fixture is in this link in the furnace process. Focus on quality, how to use the furnace jig to maximize the yield rate and reduce the poor soldering phenomenon such as continuous tin, little tin, and tin shortage is the long-term task of the processing plant.

3. Programming

When conditions permit, you can communicate with the customer to provide the back-end program, and then burn the PCBA program into the core master IC through the burner. In this way, the circuit board can be tested more concisely through touch action, so that the integrity of the entire PCBA can be tested and inspected, and defective products can be found in time.

4. PCBA test

In the processing orders of some PCBA foundry materials, some customers will require products to be tested to prevent unqualified products. The content of this test generally includes ICT (circuit test), FCT (functional test), and burn test. (Aging test), temperature and humidity test, drop test, etc.