PCB Technical - PCB tends to be high-precision

According to a survey report by Prismark, a printed circuit board (PCB) market analysis organization, China’s PCB industry will maintain a momentum of rapid growth in the next few years. From 2012 to 2017, China’s PCB output value will grow at a compound annual growth rate of about 6.0%. By 2017, the total output value can achieve 28.972 billion U.S. dollars, and its share in the global PCB market will also rise to 44.13%. On the other hand, looking at the development characteristics of the current PCB market, it can be found that due to the continuous shrinking of the consumption of personal computers and notebook computers, the terminal market is gradually tilting towards mobile communication products such as smart phones and tablet computers, and PCBs are also becoming thinner and lighter. The evolution of high-density, high-density, and multi-layer boards; coupled with the rise of wearable electronic products, the demand for flexible circuit boards has also begun to rise. All these application changes have caused a blowout in the market demand for PCB online automatic test systems. "At the same time, it is also facing severe tests.

PCB integration has risen, with more functions

The online automatic test system can be divided into two categories: online test (ICT) and functional test (FCT) according to the test content or application direction. ICT online test is mainly aimed at the quality of individual parts on the PCBA, open and short circuits on the circuit and other issues. It is equivalent to a very highly automated multimeter to find the parts and open and short circuit problems on the PCBA, and does not involve PCBA. The overall function; while the FCT test is just the opposite, it is mainly aimed at the overall function of the entire PCBA or semi-finished product/finished product, that is, it can test whether the DUT can meet the functions that the original design intends to achieve. But in short, whether it is ICT or FCT, these online automatic test systems are composed of "signal acquisition-signal conditioning-data processing-man-machine interface-report output".

The current market changes focus on automated test systems. With the advancement of manufacturing processes, the integration of PCB circuit boards is now getting higher and higher. This development trend greatly meets the needs of people for electronic products that are exquisite, compact, high-performance, sturdy and durable. At the same time, it also poses many challenges to the inspection and testing of products before leaving the factory, especially in the field of factory online automatic testing.

Although ICT, as a relatively mature application technology, has gone through decades of development, neither the press nor the flying probe can get rid of the method that requires probe contact, that is, the probe passes through the test point on the PCBA. Or the contact of the part foot, thereby applying and collecting signals, and then realizing the measurement. With the continuous improvement of the density of circuit board components, the compactness of the circuit board design has also been continuously improved, which will inevitably lead to less and less places for needle placement on the PCBA, and the needle placement is more and more difficult. This is from the source This reduces the coverage of ICT testing, which in turn affects the measurable rate of the real system. In response to this challenge, although new advanced measurement technologies have been added to the ICT system in recent years, such as TestJet and boundary scan technologies, due to technical patents and other reasons, they are all additional options for ICT and are expensive.