In the novel, a strong "bloodline" can create legends, and PCB is known as the "bloodline" of electronic products and has become an important window for breakthroughs in modern industrial technology. According to Prismark's forecast, it is estimated that by 2026, the output value of the global PCB industry will reach $101.6 billion.
Nowadays, the design of various electronic products is developing in the direction of low power consumption, low electromagnetic radiation, high reliability, miniaturization, and light weight. As the carrier of electrical interconnection of electronic components, the manufacturing process of PCB is also constantly upgrading.
In the manufacturing process of PCB, vias are usually used to connect printed wires to achieve the goal of improving electrical performance and reducing material costs. The design methods include through via, blind via and buried via. Compared with through via the use of blind via or buried via can effectively increase the density of multilayer boards, reduce the number of board layers and board size, and is suitable for high-speed circuit design.
The via design process of high-speed PCB is extremely complicated, and the precision of drilling is very high. If the via is too shallow, it cannot provide a good connection, and if the via is too deep, it will reduce the signal quality or cause distortion. Traditional manual visual inspection cannot meet the inspection needs of large quantities, and usually requires the assistance of machine vision equipment.
Let's take a look at an application case of using Hypersen's 3D line confocal sensor to detect the depth and diameter of PCB via
1. Project requirements
PCB via hole depth and diameter measurement.
2. Product model
Considering that the hole diameter and via hole spacing of PCB drilling are small, oblique beam measurement is prone to occlusion blind spots, so the coaxial 3D line spectrum confocal sensor HPS-LCX1000 with small point spacing, dense measurement points, and good angular compatibility can be selected Cooperate with the controller HPS-NB3200 for measurement.
3. Test deployment
i. Build a test platform indoors to ensure normal room temperature and normal operation of test equipment;
ii. Adjust the approximate distance between the sensor head and the measured object, and use the client to adjust the measurement signal;
iii. Set measurement parameters: Scanning Frequency 4000Hz, Sampling Point Interval 1.1μm；Line Interval 4μm, Sampling Speed 16mm/s;
iv. Organize measurement data, summarize and analyze.
4. Detection Effect
5. Testing Summary
After scanning the PCB sample, the grayscale image can be used to measure the depth and diameter of the specified blind via.
In addition, the position and shape of the via hole can be well presented on the 3D point cloud, and the height change at different positions of the PCB board can be distinguished through color discrimination.
From the table below, you can see the diameter and height data of the inner and outer rings of the 10 marked points. The measurement of different points will cause differences in test results due to factors such as machine error, ink pens and other factors. The specific effect may still depend on the actual measurement environment.
There are many PCB appearance inspection items. In addition to the measurement of hole depth, the inspection of via holes also includes aperture size, location and size of via holes, etc., while the inspection of via PCB body is more complicated, such as BGA package, wire layout, board surface details, shape and size, etc., these also need to deploy a variety of detection equipment to cooperate with each other. With the development of information technology, the product camp of machine vision is constantly enriched. As a "new technology" category, chromatic confocal sensors have unique advantages. The detection is not limited to the type of material, with high precision, strong stability and fast detection frequency, which is very suitable for in the online measurement of various highly reflective, strong light-absorbing and transparent objects, the future market prospect is broad.
As a domestic first-line high-end smart sensor manufacturing enterprise, Hypersen has been deeply involved in technology research and development and innovation. It has mastered a number of independent core technologies in the field of spectral confocal, and has successively launched a variety of cutting-edge 2D/3D detection sensors to fill the gap in the domestic technology market. Up to now, Hypersen has become the only manufacturer in the world that has product series of point spectrum, oblique line spectrum and coaxial line spectrum at the same time. Looking into the future, Hypersen will continue to launch more high-performance, easy-to-use and reliable smart sensor products and professional solutions based on market demand, empowering industrial intelligent manufacturing!