What is the key function test (KFT)? Introduction to IC chip detection

Date：2022-01-04 14:38:00Views：1769

Since each functional element has its own test requirements, the design engineer must make test planning at the early stage of design. Chip is the product of modern top high-tech technology. Chip exists in a variety of electronic products. The high integration of chip also makes the chip have more and more powerful functions. What tests does the chip need to do? It is mainly divided into three categories: chip function test, performance test and reliability test. The three tests for chip products to be listed are indispensable.

What are the key function tests? Key function test (KFT) is a dynamic test method, also known as main function test or overall function test. It refers to various necessary logic or signal state tests under specific working conditions (i.e. normal operating environment of the device, usually normal temperature), regardless of the limit parameters of the device (such as maximum / minimum parameters), and under the normal working state of the device. According to the original specifications, application notes or customer application site, as well as industry standards or specifications, this test designs feasibility test vectors or special test circuits, applies corresponding effective excitation (signal source) input to the test samples, and adopts specific conditions such as regulation and control of peripheral circuits, signal amplification or conversion matching, Analyze the logic relationship of the signal and the change state of the output waveform, and detect the functional characteristics of the device.

There are six common methods for chip function test, including board level test, wafer CP test, finished product ft test after packaging, system level SLT test and reliability test.

The first is board level testing, which is mainly used for function testing. PCB + chip is used to build a "simulated" chip working environment, lead out the interfaces of the chip, detect the function of the chip, or see whether the chip can work normally under various harsh environments. The equipment to be applied is mainly instruments and meters, and the EVB evaluation board needs to be made.

The second type: system level SLT test is often used in function test, performance test and reliability test. It often exists as a supplement to finished product ft test. As the name suggests, it is to test in a system environment, that is, put the chip into its normal working environment to run the function to test its quality. The disadvantage is that it can only cover part of the functions, The coverage rate is low, so it is generally a supplementary means of ft.

The third kind: reliability test is mainly to apply various harsh environments to the chip, such as ESD static electricity, which is to simulate human body or industrial body to add instantaneous high voltage to the chip.

Fourth: ft test of finished products after packaging is often used in function test, performance test and reliability test to check whether the chip function is normal and whether there are defects in the packaging process, and help to detect whether the chip after "fire, snow and lightning" can still work in the reliability test.

Fifth: wafer CP test is often used in function test and performance test to understand whether the chip function is normal and screen out the faulty chips in the chip wafer.

The sixth is to develop multiple strategies at the same time.

I believe that by reading the above content, we have a preliminary understanding of IC chip function detection. At the same time, we also hope that we can make a summary in the learning process, so as to continuously improve our professional level. Shenzhen Chuangxin Online Testing Technology Co., Ltd. is a professional testing organization for electronic components. At present, it mainly provides integrated circuit testing services such as capacitance, resistance, connector, MCU, CPLD, FPGA and DSP. Specializing in functional testing of electronic components, incoming appearance testing of electronic components, anatomical testing of electronic components, acetone testing, X-ray scanning testing of electronic components and RoHS component analysis testing.