What are the common methods for chip function testing? Recommend 6 simple and efficient

Date：2022-06-01 15:20:14Views：2194

With the increasing demand for miniaturization of electronic devices, the functions of single chip are increasing. In the current process, in order to ensure the quality of chips, chip detection is generally carried out in the process from design and molding to mass production. The traditional chip debugging technology is to add a set of function oriented test program on the basis of chip functions. It can only detect whether the chip has errors or faults, and can not accurately locate the errors on the chip terminal. It can only be judged according to the experience of testers, which will cause slow chip detection speed and low efficiency. Since each functional element has its own test requirements, the design engineer must make a test plan at the early design stage.

Chip function test method

There are six common methods for chip function test, including board level test, wafer CP test, FT test of finished products after packaging, system level SLT test, and reliability test. Multiple strategies are taken simultaneously.

The first type: board level test, which is mainly used for function test, uses PCB + chip to build a "simulated" chip working environment, leads out the chip interfaces, tests the chip functions, or checks whether the chip can work normally under various harsh environments. The equipment that needs to be applied is mainly instruments and meters, and the EVB evaluation board needs to be made.

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

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

The fourth type: 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 to help detect whether the chip after "fire, snow and lightning" can still work in the reliability test.

The fifth type: wafer CP test, which 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 simultaneously.

Chip test equipment

First: testing machine

The testing machine is a special device for testing the function and performance of chips. During the test, the tester applies the input signal to the chip to be tested, and compares the output signal with the expected value to judge the electrical performance of the chip and the effectiveness of the product function. In the CP and FT detection links, the test opportunity transmits the results to the probe table and the sorter respectively. When the probe stage receives the test results, it will conduct inkjet operation to mark the chips with defects on the wafer; When the sorter receives the results from the tester, it will choose and classify the chips.

Second: probe machine

The probe table is used for CP testing after wafer processing and before packaging process. It is responsible for wafer transportation and positioning, so that the grains on the wafer can contact the probe in turn and test one by one. The working process of the probe stage is as follows: move the wafer under the wafer camera through the slide stage - shoot the wafer image through the wafer camera to determine the wafer position - move the probe camera under the probe card to determine the position of the probe head - move the wafer under the probe card - realize needle alignment through the vertical movement of the slide stage.

Third: sorter

The sorting equipment is used in the FT test after chip packaging. It is a post test equipment that provides chip screening and sorting functions. The sorter is responsible for transporting the input chips to the test module to complete the circuit voltage test according to the system design. In this step, the sorter chooses and classifies the circuits according to the test results.

As the core component of electronic products, the performance of chips tends to be better and better. In order to ensure the quality of chips, people have adopted effective testing technology to test the functions of chips. Wafer verification: with the increase of design complexity, the workload and operation difficulty increase by an order of magnitude. The biggest challenge for the verification engineer is to run complex simulation in the design engineering, describe the chip product specification into various functions in the form of binary waveform, deal with the complex state space, and detect its errors.

The above is related to the chip function test organized by the creative core testing team. I hope it can help you. Shenzhen Chuangxin Online Testing Technology Co., Ltd. is a well-known professional testing institution for electronic components in China, with 3 standardized laboratories covering an area of more than 1000 square meters. The scope of testing services covers: testing and verification of electronic components, IC authenticity identification, material selection for product design, failure analysis, function testing, factory incoming material inspection, X-ray testing of components and parts, tape braiding and other testing items.