This article is a sharing of the second prize works of the 2023 Seventh National College Student Integrated Circuit Innovation and Entrepreneurship Competition ("Integrated Circuit Competition") Accelerated Technology Cup. Participate in the [Prize-winning Collection] of Jishu Community to share your 2023 Integrated Circuit Competition works, show Show off the style of your works, share your 2023 competition creations to expand your influence, and there are rich electronic gifts waiting for you!
team introduction
Participating unit: North University of China
Instructors: Zhao Rui, Li Zhonghao
Team members: Zheng Hao, Li Guohao, Zheng Ke
Final award: Second Prize of the Northwest Division of "Aerospace Microelectronics Cup"
write in front
The members of our team are quite satisfied with the results of this competition. Although we are disappointed that we did not win the first prize, the rewards brought to us by a wonderful competition have exceeded the value of the award itself. An excellent university and a group of excellent students allowed the students in our team to see the gap, muster up motivation, clarify the direction of their efforts, and determine to achieve better results in next year's competition.
Looking back on the process of this competition, it is really unforgettable. This is our first time to participate in this competition, from topic selection to preparation, we are all trying to cross the river by feeling the stones. Under the guidance of the teacher, we focused on the current situation of the industry, that is, with the rapid development of my country's integrated circuit and semiconductor industries, the testing of integrated circuit chips has become a key link between integrated circuit design and manufacturing, packaging and applications. part, throughout the entire production and application process of IC. We design an IC chip to meet the corresponding application requirements, but there are inevitably many problems during the entire design and manufacturing process, resulting in problems and defects in the produced chips.
Therefore, before the chips leave the factory, they must be qualified and tested to select those defective chips, thereby reducing unnecessary cost consumption. Under this purpose, we note that power supply technology is constantly developing towards high speed and high frequency. As the frequency continues to increase, this brings unprecedented challenges to how to accurately test its dynamic parameters and static parameters.
Under these two realistic industry backgrounds and needs, we clarified the direction of our topic selection, which is power chip test design and performance analysis based on ATE.
This topic was chosen in response to the needs of the times.
Design brief
DC parameter test design
DC parameters mainly include power supply current IQ, output high and low levels VOHL and conversion level VIHL, etc.
Rdson test
In the ATE test, we do not use conventional testing methods, but use the Kelvin connection method to measure resistance. Kelvin connection, also called four-wire connection, is a method of measuring tiny resistances. It can effectively remove the influence of wire resistance and other miscellaneous items on the tiny resistance, making the test results more accurate.
Open and short circuit test
This test is used to check whether the electrical characteristics of the signal pins of the chip are connected normally, and there is no short circuit between the signal pins or between the signal pins and the power supply or ground. In production testing, the test time often determines the test cost. It is very necessary to end the test of defective chips early. Therefore, the test time of open short circuit and leakage current is shorter, and to a certain extent, it can be more comprehensive. It is a common practice in the testing process to put the test items that detect defective chips at the front.
Leakage current test
Under ideal process conditions, it can be considered that the current between the control terminal of the MOS tube and the input and output terminals of the conductive path is approximately zero. But in fact, there are always some electrons that pass through the silicon oxide layer and reach the control end, forming a leakage current. When the leakage current is too large, it will affect the electrical characteristics of the MOS tube, thereby affecting the characteristics of the entire circuit, and even preventing it from working properly. . Therefore, the leakage current must be limited within a certain range. When the leakage current exceeds this range, it can be determined that this is a defective circuit.
AC Parametric Test Design
AC parameter testing and functional testing are closely related. When performing AC parameter testing, the appropriate timing parameters (such as cycle, driving edge position, comparison edge position, etc.) and signal format (such as signal waveform) need to be set in advance for calling. parameters to be measured, and then a series of test vectors will be executed to ensure that all the preset AC parameters can be tested.
Minimum on/off time test
According to the design requirements, the chip has two soft-start mechanisms. One of them is used to prevent surge current when the circuit is started. When VFB is less than 0.6V, the minimum off-time of the inductor is extended from Minon to minOff.
Fuse trim
Fuse trimming is a very common trimming method. The implementation principle is relatively simple, that is, by blowing the fuse between different resistors inside the circuit, the resistance value of the resistor network is changed, thereby changing the output voltage.
Test results and efficiency
Rdson test results
Use the designed ATE test system to test the ADP2381 at 25°C and collect data.
The leakage current test results and the minimum on/off time test results can be obtained in the same way as above and will not be shown here.
Summary
Here are actual shots of the prototype test.
Here are real shots of pre-match training.
Due to our lack of experience in this competition, we neglected that in addition to focusing on the technological innovation of products, this competition should also focus on the commercial value of innovation and entrepreneurship. This may be one of the reasons why we failed to win the first prize in the competition.
Participate in the [Prize Collection] of the Jishu community and share your 2023 original competition works to show off the style of your works. Share your 2023 original competition works to expand your influence. There are also rich electronic gifts waiting for you!
For more works shared in the IC Technology Competition, please pay attention to the sharing of IC Technology Competition works .