What links must we know about one-stop PCBA assembly and processing?

What links must we know about one-stop PCBA assembly and processing?

The circuit board manufacturer, circuit board design and PCBA processing manufacturer explain to you which links must be known in one-stop PCBA assembly and processing?

PCBA is a series of processing processes including PCB manufacturing, component procurement and inspection, SMT chip processing, plug-in processing, program firing, testing, aging, etc. PCBA processing involves many links, so we must control the quality of each link to produce good products.

1. PCB manufacturing

After receiving the order from PCBA, analyze the Gerber file, pay attention to the relationship between the hole spacing of PCB and the bearing capacity of the board, do not cause bending or fracture, and whether the wiring takes into account the high-frequency signal interference, impedance and other key factors.

2. Procurement and inspection of components

The procurement of components needs to strictly control the channels, and must pick up the goods from large traders and the original factory to avoid 100% second-hand and fake materials. In addition, special incoming material inspection posts shall be set up to strictly check the following items to ensure that components are free of failure.

PCB: reflow soldering furnace temperature test, no flying wire, whether the via is blocked or leaks ink, whether the board surface is bent, etc;

IC: Check whether the silk screen is completely consistent with the BOM, and store it at constant temperature and humidity;

Other common materials: check silk screen, appearance, power on measurement value, etc. The inspection items are carried out according to the sampling method, and the proportion is generally 1-3%.

3. SMT chip processing

The temperature control of solder paste printing and reflow soldering furnace is the key point. It is very important to use laser steel mesh with good quality and meeting the process requirements. According to the requirements of PCB, some of the steel mesh holes need to be increased or reduced, or U-shaped holes are used to make the steel mesh according to the process requirements. The temperature and speed control of reflow soldering furnace is very important for solder paste infiltration and welding reliability. It can be controlled according to normal SOP operation guidelines. In addition, AOI detection needs to be strictly implemented to minimize defects caused by human factors.

4. DIP plug-in processing

In the process of plug-in, the mold design of wave soldering is the key point. How to use the mold to maximize the probability of good products after the furnace is a process that PE engineers must constantly practice and summarize experience.

5. Programmed firing

In the previous DFM report, customers can be advised to set some test points on the PCB to test the continuity of PCB and PCBA circuit after all components are welded. If conditions permit, the customer can be required to provide the program. The program can be burned into the main control IC through the burner, so that the functional changes caused by various touch actions can be tested more intuitively, so as to check the functional integrity of the whole PCBA.

6. PCBA board test

For orders with PCBA test requirements, the main test contents include ICT, FCT, aging test, temperature and humidity test, drop test, etc., which can be operated according to the customer's test plan and the report data can be summarized.

The circuit board manufacturer, circuit board design and PCBA processing manufacturer explain to you which links must be known in one-stop PCBA assembly and processing?