The Introduction to PCB flying Probe test

In the production process of PCB board, it is inevitable that due to external factors, which cause electrical defects such as short circuit, disconnection, and leakage, PCB line board continues to evolve at high density, thin spacing, and multi-level. Bad board screening is screened, and in the process of allowing its inflow process, it is bound to cause more waste. Therefore, in addition to the improvement of process control, the improvement of testing technology can also provide PCB board manufacturers with reduced scrap rate and improved product benefits. s solution. Now let’s discuss some PCB testing equipment.

There are two types of PCBA circuit test (ICT): one with a fixed device (type of nail bed) and the other without a fixed device (Flying Probe). Deploy ICT for a range of tests – from several test points for basic short-circuit testing to tens of thousands of test points for more complex PCBAs.

Since the late 1980s, the Flying Probe tester has been on the market. It was originally intended to complete a simple task, i.e. the circuit test prototype without good test points. Unlike the need for expensive fixed devices and the unreasonable nail bed ICT for prototypes or small batches of PCBA, the Flying Probe tester is currently widely used in various fields of the electronic manufacturing industry. In addition, it is very easy to create initial testing procedures from PCB design files without traditional nail bed test fixtures. As a result, the total development time of the Flying Probe test program has been greatly reduced by several hours. Since then, it has gained attention in terms of complexity and popularity.

Test and measurement method of Flying Probes:
Flying Prober uses a small number of fixed and active probes for contact instead of using a nail bed. Fixed pins are usually used to contact the power grid. Electromechanical control pins (contact fingers) that move in the X / Y direction are exposed to all other circuit nodes in order. Generally, the PC board is upside down in the tester. Multiple arms with a test probe are moved to the bottom of the plate, which touches the test point and measures

The flight probe tester usually checks short circuits, open paths, resistance, capacitors and other basic quantities, which will show whether the component is configured correctly. It can locate the defect without professional technical personnel and special tools, which are easy to repair quickly and efficiently. The precise operation of the test probe (PCB with a minimum of 0.3mm, smaller and repeatable accuracy of+/- 0.05mm) can effectively check the raised feet and dry joints raised on the IC package.

Some manufacturers stated that their system has sufficient accuracy and can detect IC types including PLCC, SOIC, PGA, SSOP, QFP, etc.

The system can be partially extended to include other test methods, such as border scanning, programming on board storage modules, optical inspection (AOI), functional testing, or heat inspection to achieve different solutions. Some examples:

• The camera is used for the existence and correct direction of test components

• Optical detector to test the color and strength of the LED

• The external timer counter module is used to test the crystal and oscillator of a very high frequency (more than 50 MHz)
Field of application of Flying Probe test:
In principle, the Flying Probe tester can be used in three different application areas. The functions and characteristics of testers are different.

Advantages of Flying Probe test:
• Save test preparation time, the cost of no production tool
• Quickly programming the test program, the design changes are added and integrated through simple operations
• Highly flexible flexible test
• No circuit board interface, or even a special test point, you can
• The controlled needle of the controlled needle, for any plate type, can be edited by its touch plate strength
• It can integrate a number of different test functions on one test system
• Precise positioning and measurement

PCB test:
In order to be able to perform continuity and isolation tests, these Flying Probes usually run at more than 100 volts. They are also equipped with about 20 mobile probes, which can perform high parallel tests for high throughput.

PCB assembly test:
These systems often use 4 mobile probes on both sides of the components. The probe is mainly slightly inclined, so they can also enter the contact surface between high components. High fault coverage is also important here, which means you can choose to use other test methods to supplement the system.

Maintenance test:
These systems typically use only one scanning head and one or two probes for operation. Increased analysis is used to detect component failure, and compares the measurement reading of the measurement reading with the measurement readings of non-defective components to check for any failure in a quarantine circuit node.

The flight probe tester is now widely used in the entire electronics manufacturing industry. They offer cheaper and more flexible online test forms. Applying novel and innovative design features to improve test speed, onboard access, reliability and repeatability opens up new possibilities for deploying Flying Probe tester.