Although the ICT test fixture is becoming more and more popular in the market, it is still necessary to check its equipment frequently for damage.
1. First of all, there is a big deviation. First of all, we need to check the test fixture, it is likely that the test fixture is broken.。
2. Article 2. There are insulating materials such as rosin in the test points. The existence of these materials will also lead to deviations in the test results.
3. When the copper foil on the printed circuit board breaks, the test value of the fixture has a large deviation, or the opening between Viacol and the copper foil is large.
4. Errors, missing parts, reverse loading and other phenomena in ICT test treatment will also cause deviations in test results.
5. It is also possible that the test pin of the test fixture is broken, which mainly depends on whether the equipment connected with the test pin is out of capacity.
6. Poor welding contact of the device on the test fixture may lead to deviations in the test results.
ICT test fixture components can detect component value errors, failures or damages, memory program errors, etc. In the process category, faults such as soldering short-circuit, component insertion error, reverse insertion, missing installation, pin warping, virtual soldering, PCB short-circuit, and disconnection can be found. Test faults are directly located on specific components, equipment pins and network points, and the fault location is accurate. Maintenance failure does not require much expertise. The automatic test operation of program control is simple and the test speed is fast. The test time for a single board is generally a few seconds to tens of seconds.
In order to remove the dust on the grating ruler, it should be cleaned with absolute ethanol. When cleaning, you should use rotating gloves (dipped in a small amount of absolute ethanol) to gently clean the grille in one direction, and do not scrub back and forth (so as not to scratch the grille). At the same time, it is required that the air source of the test fixture should be dry, filter oil and water, and then enter the equipment, otherwise it will affect the service life and measurement accuracy of the equipment．
ICT can effectively find various defects and failures in the SMT assembly process, but cannot evaluate the clock performance of the entire circuit board system. Functional testing can test whether the entire system can achieve the design goals. It takes the tested unit on the circuit board as a functional unit, provides input signals to it, and detects output signals according to the design requirements of the functional unit.
ICT test fixture
The ICT test fixture is mainly used to detect the open circuit and short circuit of a single component and circuit network online. It has the characteristics of simple operation, fast and accurate fault location. The ICT test fixture can test the logic functions of analog devices and digital devices. The fault coverage is high. A special needle bed is required for each kind of veneer. This needle bed is called me in industrial production. CT test equipment.
The ICT test fixture can test the electrical performance of vehicle components and the connection of the circuit network. It can quantitatively measure resistance, capacitance, inductance, crystal oscillator and other devices. It can also test the functions of diodes, transistors, optical roots, transformers, relays, operational amplifiers, power modules, etc., as well as the functions of small and medium-sized integrated circuits, such as 74 series, memory, common drivers, switch ICs, etc.
The selection of the probe is mainly based on the center distance of the circuit board of the ICT test fixture and the shape of the measuring point. The closer the point to be tested on the PCB board, the thinner the outer diameter of the selected probe. At present, the quality of domestic probes is normal. In fact, many of the so-called Taiwanese detectors are made in China.
Generally speaking, domestic probes of 0.31mm and above pass the test, and the number of tests can be guaranteed to be 200 to 150,000. Although the product is said to be 1 million times, the actual use effect is slightly higher at this level. The difference between domestic and foreign products is the wear resistance of the electroplated coating. Because the needle material is imported raw materials, there is no difference between imported products and domestic products.
ICT test fixture probes usually have a variety of specifications. The needle is mainly composed of three parts: one part is a needle tube, which is mainly gold-plated with copper alloy; the other part is a spring, which is mainly gold-plated with piano wire and spring steel; the third part is a needle, which is mainly nickel-plated or gold-plated with tool steel (SK).
As a technology partner of ICT test fixture, I believe it will be more popular in the future.