What is IC testing? Introduction to the solution of chip testing

Date：2021-07-16 14:14:43Views：6252

What is IC testing? Any integrated circuit is a single-chip module designed to complete a certain electrical characteristic function. IC test is the test of integrated circuit, which is to use various methods to detect those samples that do not meet the requirements due to physical defects in the manufacturing process. Thus, it is an important link to ensure product yield and cost control, and plays an important role in IC production process.

IC test is an important link in the production process of integrated circuits. The main purpose of the test is to ensure that the chip can fully realize the functions and performance indicators specified in the design specification under harsh environment. Each test will produce a series of test data. Since the test program is usually composed of a series of test items, the chip is fully tested from all aspects, It can not only judge whether the chip performance meets the standard and can enter the market, but also fully and quantitatively reflect various indexes of each chip from structure, function to electrical characteristics from the detailed data of test results. Therefore, testing the integrated circuit can effectively improve the yield and production efficiency of the chip.

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.

The function test is to see whether the chip is right, the performance test is to see whether the chip is good, the reliability test is to see whether the chip is firm, and the function test is to test the parameters, indicators and functions of the chip. Performance test, because there are countless possible steps to introduce defects in the production and manufacturing process of chips, even if the same batch of wafers and packaging finished products, the chips are good or bad, so they need to be screened. People say that it is to pick stones from eggs and throw away the "stone" chips. Reliability test: the chip has passed the function and performance test and got a good chip. However, whether the chip will be damaged by the most annoying static electricity in winter, whether it can work normally in thunderstorm, dog days and snowy days, and whether the chip can be used for one month, one year or ten years should be evaluated by reliability test.

What solutions do we have to implement these tests?

Test methods: board level test, wafer CP test, FT test of finished products after packaging, system level SLT test and reliability test.

Board level test is mainly used for function test. 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.

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. CP [chip probing], as the name suggests, is to use the probe to tie the chip on wafer, input various signals into the chip, grab the chip output response, compare and calculate it. There are also some special scenarios to configure and adjust the chip [trim]. The equipment to be applied is mainly automatic test equipment [ate] + probe table [probe] + instruments, and the hardware to be made is probe card [probe card].

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 detect whether the chip after "fire, snow and lightning" can still work in reliability test. The equipment to be applied is mainly automatic test equipment [ate] + manipulator] + instruments, and the hardware to be made is test board [loadboard] + test socket [socket].

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 some functions, The coverage rate is low, so it is generally a supplementary means of ft. The equipment to be applied is mainly the manipulator, and the hardware to be made is the system board + test socket.

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. Another example is aging HTOL [high temperature operating life], which is to accelerate chip aging at high temperature and then estimate chip life. In addition, the hast [highly accelerated stress test] tests the moisture resistance of the chip package. The product to be tested is tested under severe temperature, humidity and pressure. Whether the moisture will penetrate into the package along the colloid or the interface between the colloid and the lead frame, thereby damaging the chip.

The above is the whole content of "what is IC testing? Introduction to the solutions to realize chip testing". Due to the defects brought by the actual manufacturing process and the material itself, no matter how perfect the product will produce bad individuals, so testing has become one of the indispensable projects in integrated circuit manufacturing.