What equipment is required for chip testing? Main methods of chip function test

Date：2022-12-02 15:14:58Views：1066

In recent years, the demand of semiconductor equipment market in Chinese Mainland has grown rapidly. In this context, the high-precision detection equipment that must be used for chip wafer detection also has an increasingly broad market. Because each functional component has its own test requirements, the design engineer must make a test plan at the beginning of the design. This paper collects and sorts out some materials, hoping to be of great reference value to all readers.

1、 What equipment is required for chip testing?

First: testing machine

The testing machine is a special equipment to test the function and performance of the chip. During the test, the tester applies the input signal to the chip to be tested, and the output signal is compared 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 station receives the test results, it will conduct inkjet operation to mark the defective chips on the wafer; When the sorter receives the results from the tester, it will select and classify the chips.

Second: probe machine

The probe table is used for CP testing after wafer processing and before packaging process, which is responsible for wafer transportation and positioning, so that the grains on the wafer contact the probe in turn and test one by one. The working process of the probe station is: move the wafer under the wafer camera through the chip carrier station - take the wafer image through the wafer camera to determine the wafer position - move the probe camera under the probe card to determine the probe head position - move the wafer under the probe card - achieve needle alignment through the vertical movement of the chip carrier.

Third: Sorter

Sorting equipment is used in the FT test link after chip packaging. It is a post test equipment that provides chip screening and classification functions. The sorter is responsible for transporting the input chips to the test module according to the picking and placing method designed by the system to complete the circuit pressure test. In this step, the sorter selects and classifies the circuits according to the test results.

2、 Several common methods of chip function test

There are six commonly used methods for chip function testing, including board level testing, wafer CP testing, packaged finished product FT testing, system level SLT testing, and reliability testing.

The first type is board level testing, which is mainly used for functional testing. It uses PCB+chip to build a "analog" chip working environment, leads out all the interfaces of the chip, detects the function of the chip, or checks whether the chip can work normally in various harsh environments. The equipment to be applied is mainly instruments, and the EVB evaluation board needs to be made.

The second type: system level SLT testing, which is often used in functional testing, performance testing and reliability testing, often exists as a supplement to FT testing of finished products. As the name implies, testing is carried out in a system environment, that is, the chip is placed in its normal working environment to run functions to detect its quality. The disadvantage is that it can only cover a part of the functions, and the coverage is low, so it is generally a supplement to FT.

The third type: reliability test, which mainly applies various harsh environments to the chip, such as ESD static electricity, is to simulate a human body or an industrial body to apply a transient high voltage to the chip.

The fourth type: FT test of finished products after packaging, which is often used in function test, performance test and reliability test to check whether the chip functions normally and whether there are defects during packaging, and to help detect whether the chip can work after "fire, snow, thunder and lightning" in reliability test.

The fifth type: wafer CP test, which is often used in function test and performance test to understand whether the chip functions normally and screen out the faulty chips in the chip wafer.

The sixth is to develop multiple strategies simultaneously.

In conclusion, in each link of semiconductor design, manufacturing and packaging, repeated inspections and tests should be carried out to ensure product quality, so as to develop devices that meet the system requirements. The cost of defect related failures is high, ranging from tens of dollars at the IC level to hundreds of dollars at the module level, and even thousands of dollars at the application end level. Therefore, detection equipment plays an irreplaceable role from design verification to the entire semiconductor manufacturing process. Our company has a team of professional engineers and industry elites, and has built three standardized laboratories with an area of more than 1800 square meters, which can undertake a variety of test projects such as electronic component test verification, IC authenticity identification, product design material selection, failure analysis, functional testing, factory incoming material inspection and tape weaving.