Importance of in-Circuit Test

In the advent of electronic test equipment, component binning was one of the foundational types of automated test process adopted by FABs that has led to radical advancement in the technology we see today.

ICT is a process of development where the manufacturer and PCBA test equipment provider, Designs for Testing an Assembled Printed Circuit Board (DFT for PCBA) where the manufacturer provides data required for DFT and the Test equipment provider recommends a design for the PCB development that provides maximum test coverage for PCBA.

The in-circuit test is the only way a manufacturer can determine if the circuit under test is produced as per design with high speed and accuracy. In-circuit test are essential for applications where errors are least expected such as Space Tech, Military Tech, Defense, Safety, High tech Equipment, Automobiles, Oil rigs & Platforms, Medical equipment, etc. as they may encounter huge losses or may be life-threatening.

It is a common mistake that manufacturers make to skip ICT and opt for a Function test. Well, a Function Test (FT) or End-line test (EOL) will only portray the signal, and parameters and simulate the functioning of the unit under test but, it does not present the details for analysis where the user can determine if the assembled circuit have any faulty components or values that astray due to damage at time of assembly. If such inconsistencies are not taken care of, then it is bound to fail. ICT gives the manufacturer the ability to maintain flawless quality of production where a warranty can be offered and brand value is maintained without loss.

ICT gives the manufacturer the ability to identify issues in the early stage of production which saves time, and resources and renders durable products thus, thus granting sustainability which is most important for the future and must be an integral part of Industry 4.0.

Kyoritsu Electric India offer Focus Series of ICT machines that are very accurate, test at high speed and complete technical support with custom designed test Jigs that allow manufacturers to have control over the quality and offer the best results to their customers.

Focus 2000 (ICT) & 4000 (Combo- ICT+FCT) Series testers vs. Conventional Reed-relay based MDAs

In-circuit testing is a field where assembled circuits are tested for their performance in every component for which the performance of ICT test machines has to be very accurate, consistent, and stable.

MPX Cards in ICT machines which are multiplexed switches are the first functional block of the machine that is interfaced with the circuit under test via test probes. For any machine to perform ICT tests it is critical to have a clean interface.

This article presents the knowledge about ICT machines' circuit interface modules and available revolutionary technology that helps users to understand and discriminate test systems for their application.

The most important component to be discussed is the MUX Switching which can be performed by Relay, Reed relay, Solid state relay, Ultra- Advanced CMOS Digital Switch, etc. Which Reed relays are commonly used by manufacturers of MDAs worldwide for quick verification in comparing and identifying errors with respect to mounted components on the board. Though these reed relay-based testers are always price-economical however, they degrade in performance since operation in vacuum and inert gas only solves the problem of oxidation but the formation of surface irregularities persists and linearly introduces resistance over time. Therefore, in in-circuit component testing it affects actual test measurement value & and to pass components, you need to apply a very high tolerance value (almost 30-40% plus) of the component value.

Kyoritsu has patented Ultra Advanced Solid-State CMOS Digital Switching Technology and direct computer control through PCIe to measurement boards without using a co-processor. Focus 2000 (ICT + MDA) and 4000 (ICT + MDA + FCT) are truly state-of-art machines with the design capability that enables circuit testing with almost in range of close tolerances of the components in testing domain and the test results are most accurate, consistent and stable.