How to Control PCB Assemby Quality

PCBA is a complicated processing . problems in any link will lead to poor product processing, how to control the quality of PCBA processing?This requires the establishment of a set of perfect ISO quality control system, each position in accordance with the operation instructions to operate, to avoid the negative impact of human factors.

From raw material procurement to production and processing to the final shipment inspection need strict standard control, strictly implement the ISO9001:2008 quality management system, and in accordance with the IPC-A-610E electronic assembly acceptance standards for production.

The ISO review organization strictly reviews the PCBA processing and production quality control plan of the company, establishes the production site to meet the standard and carries out the quality control plan and measures according to the provisions.


1.PCB circuit manufacturer

When get the pcba order ,facttory will check the gerber file ,Focus on between PCB hole spacing and plate bearing capacity,Do not cause bending or breaking, wiring whether to consider the interference of high frequency signal, impedance and other key factors.

Components purchasing need to control strict ,Always pick up goods from large traders and original manufacturers and avoid 100% used and fake materials.In addition, special incoming material inspection posts are set up to strictly check the following items to ensure that components have no faults.Set up a special incoming material inspection post, strictly check the following items, to ensure the components without failure.

PCB: reflow furnace temperature test, no fly line, whether hole blocking or ink leakage, whether the board is bent, etc.

C: Check whether the silkscreen is exactly the same as BOM, and do constant temperature and humidity preservation;

Other common materials: check silk screen, appearance, power measurement value, etc., check items in accordance with sampling inspection, the proportion is generally 1-3%.

2.SMT Assembly process

Solder paste printing and reflow furnace temperature control are the key points. It is very important to use laser steel mesh with good quality and in line with technological requirements.According to the requirements of PCB, some steel mesh holes should be increased or reduced, or u-shaped holes should be used to make steel mesh according to the process requirements.Reflow furnace temperature and speed control are critical to solder paste infiltration and soldering reliability, and can be controlled according to normal SOP operating guidelines.In addition, AOI testing needs to be strictly implemented to minimize the adverse effects caused by human factors.


3.DIPAssembly Processing

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


4.Programming uploding

In the early DFM report, the customer can be suggested to set some Test Points on the PCB, in order to Test the PCB and the PCBA circuit connectivity after all the components are welded.If conditions are available, customers can be required to provide procedures, through the burner (such as ST-link, J-Link, etc.) will be fired into the main control IC program, you can more intuitively test the functional changes brought by all kinds of touch action, in order to test the integrity of the whole PCBA function.


  1. PCBA board test

For orders with PCBA Test requirements, the Test content mainly includes ICT(In Circuit Test), FCT(Function Test), Burn In Test(aging Test), temperature and humidity Test, drop Test, etc. The specific operation and report data can be summarized according to the customer’s Test plan.