PCB News - PCB circuit board quality control

PCB circuit board quality control

The quality control of PCB circuit boards is mainly aimed at the effective management, monitoring and measurement of the design, processing and inspection process of printed boards.

1. Quality control in the design stage

The quality control work in the design stage mainly includes the following contents.

(1) The person in charge of the project shall review the design documents of the printed circuit board and perform relevant approval procedures to ensure that the design documents are legal and effective. The printed circuit board produced according to this document can meet the function and performance requirements of the equipment, otherwise no matter how good the design is, it will be a pile of waste paper.

(2) The standardization division conducts a normative review of the test points, structural forms, dimensions, printed line layouts, pads, cross-holes, characters, etc. of the printed circuit board to ensure the testability and specification of the printed circuit board To meet the requirements of relevant national standards, national military standards and industry standards as much as possible.

(3) The person in charge of the project and the technologist should check the process requirements of the printed circuit board production to ensure the manufacturability of the printed circuit board. If the process requirements are simple, they can be listed directly on the design drawings, and if the content is more, they can be written separately. Regardless of whether the process requirements are simple or complex, they should be accurate, clear, and methodical to indicate the process requirements. The audited process requirements should not only meet the current production process level, be economical, cost-effective, and facilitate subsequent assembly, debugging, inspection and other processes.

2. The quality control of PCB circuit board processing stage

The quality control work of the circuit board processing stage mainly includes the following contents.

(1) The quality department, together with the purchasing department, conduct on-site inspection and certification of the qualifications and production capacity of the PCB circuit board manufacturer to ensure that the PCB circuit board manufacturer has the ability to complete the production task.

(2) The designer shall re-examine the drawings used by the PCB circuit board manufacturer for production. Because the design of the printed board is often not a success at one time, it needs to be revised many times. PCB circuit board manufacturers have multiple versions of processing drawings, so it is necessary to reconfirm the final processing drawings to ensure that the processed printed boards meet the requirements of the final version.

(3) Focus on the key processes in the production of printed circuit boards. Its quality has a great influence on the performance and reliability of the printed board, and quality control should be strengthened. Supervise and review the key process procedures established by the manufacturer, such as etching and hole metallization, to ensure that the printed lines and pads are free of burrs, gaps, and bridge defects, and the vias are free of nodules and voids. The "lamination" of multi-layer printed boards should also focus on quality control to ensure the thickness, bonding strength and positioning accuracy of the printed boards. High-frequency boards and usually need to be gold-plated, and special gold-plating process instructions should be formulated to ensure the thickness and purity of the plating.

3. Quality control in the inspection phase

The quality control work in the inspection phase is to strictly follow the inspection basis, monitor and measure the printed board through visual inspection or use special tooling and instruments, and keep records. If there are special requirements, special inspection rules should be formulated.