PCB Technical - Process flow of via via on circuit board

Process flow of via via on circuit board

PCB circuit board via (via) technology is the core of quality control, and it also accounts for about 30 to 40% of the entire PCB manufacturing cost, because it has a pivotal position. The use of scientific and standardized via process and drilling equipment, and equipped with professional inspection procedures are the basis for ensuring the quality of via vias on PCB circuit boards.

1. The basic concept of via via
Via vias are circular apertures that penetrate the circuit board. According to their functions, they can be divided into signal vias, power/ground vias, and heat dissipation vias. Among them, signal vias are the most common. Signal vias are mainly used for electrical connections between multiple layers of the PCB and positioning of components. In terms of process classification, signal vias (via) are divided into blind vias, buried vias and through vias.

2. Via via process flow
To complete the PCB via hole, you must use a professional drilling machine, such as Hitachi, Schmoll, Timax and other brands. The PCB substrate is fixed on the drilling machine, the drill bit that meets the hole diameter requirement is assembled, the drilling coordinate program in the PCB file is input on the drilling machine, and the corresponding drilling speed is adjusted to complete the drilling process. In the via process, drilling accuracy, position deviation, drill bit breakage, etc. must be monitored in real time, and problems can be solved in time.

3. Via via device
PCB drilling machine

Drilling machine is the most important device for via hole. There are many styles and functions in the market. PCB factory selection can be evaluated based on the following factors:

A. Number of axes: directly related to output
B. Effective drill plate size
C. Drilling machine table: Choose a material with low vibration and flat strength.
D. Bearing (Spindle)
E. Drilling disc: automatically replace the drill bit and the number of drill bits
F. Pressure feet
G. X, Y and Z axis transmission and size: accuracy, X, Y independent movement
H. Dust collection system: with pressure feet, good chip removal, and drill bit cooling function
I. Step Drill's ability
J. Broken needle detection
K. RUN OUT

4. Process precautions for via vias
In the via process, the following failures often occur, and operators and process personnel need to have a wealth of problem identification and resolution capabilities.

A. Broken cobalt nozzle
B. Pore loss
C. Hole position offset, misalignment
D. Distorted via size
E. Leak drilling
F. Phi Feng
G. The via is not drilled through
H. Curly debris appears on the panel
I. Blocked vias

The via process of PCB circuit board is one of the most critical links in the entire manufacturing process of the circuit board manufacturer, which determines the quality and electrical connection performance of the PCB, and is also an important node for mass scrap or rework. Therefore, every PCB factory will establish a strong and complete mechanism in terms of process documentation, personnel control, and inspection procedures to ensure the good operation of batch PCB production.

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