PCB Technical - PCB online automatic test system demand "blowout"

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 current development characteristics of the PCB market, it can be found that due to the continuous shrinking of the consumption of computers and notebooks, 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, multi-layer boards; coupled with the rise of wearable products, the demand for flexible circuit boards has also begun to rise. All these application changes have caused PCB online automatic test systems to "blow out" in the market demand. At the same time, it is also facing severe tests.

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 testing is mainly for the quality of individual parts on the PCBA, open and short circuits on the circuit, etc. It is equivalent to a very high degree of automation multimeter, to find the parts on the PCBA, open and short problems, and does not involve the overall PCBA Function; 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 wants 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".

With the advancement of manufacturing technology, the integration level of PCB circuit boards is now higher and higher. This development trend greatly meets the needs of people for electronic products such as exquisite, compact, high-performance, strong and durable. Inspection and testing posed many challenges, 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 entire 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 technology, due to technical patents and other reasons, they are all additional options for ICT and are expensive.

On the other hand, FCT, as another branch of the online automatic test system, also faces the need for a comprehensive upgrade. Since FCT focuses on the overall function test, the increase in the density of PCB components does not have much impact on the front end of the system, that is, the UUT contact interface. However, as the density of circuit boards continues to increase and integration is gradually increasing, its functions are also more abundant and diversified. This puts forward more comprehensive and efficient requirements for modern automated test systems, and promotes FCT functional testing to be fully automated. The direction of development.