The previous section introduced the basic test classification and testing process. This section mainly talks about our common test projects , test plans and test procedures .
Common test items for IC are generally
- Direct current (DC) parameter test
- AC Parameter Test
- function test
- Mixed signal parametric testing
The test items included in the DC parameter test generally include open-short circuit test (Open-Short, OS), input/output current test, input/output voltage test (mostly input/output power test in RF), power consumption test, input/output Offset test and gain test, etc. The following table is the DC parameter table of a certain product
| parameter | Test Conditions | SN5400 | SN7400 | unit | ||||
| MIN | TYP | MAX | MIN | TYP | MAX | |||
| Voh | VCC=MIN,Vil=0.8V Ioh=-0.4mA | 2.4 | 3.4 | 2.4 | 3.4 | V | ||
| Vol | VCC=MIN,Vih=2V Iol=16mA | 0.2 | 0.4 | 0.2 | 0.4 | V | ||
| II | VCC=MAX,V1=5.5V | 1 | 1 | mA | ||||
| Iih | VCC=MAX,V1=2.4V | 40 | 40 | uA | ||||
| Iil | VCC=MAX,V1=0.4V | -1.6 | -1.6 | mA | ||||
| Ios | VCC=MAX | -20 | -55 | -20 | -55 | mA | ||
AC parameter test is a test of time parameters related to product input and output, such as AC related parameters, frequency test and time jitter test, etc. This part of the product parameter table will also be given.
Functional testing is mainly to verify whether the IC can perform normal functional operations according to the logic of the truth table. The logical function expressed by the truth table is to apply a specific pattern to the DUT as input, and then compare the output with the preset expected value to determine whether the function is normal. This part will be used in future DPE software and will be explained in detail.
Mixed-signal testing is the testing of static parameters and dynamic parameters related to digital-to-analog/analog-to-digital conversion.
Test Plan Test Plan is also called Test Specification, which records the detailed requirements of test projects executed step by step. Before understanding Spac, you generally need to read the product manual first. Understanding product functions, features, pin descriptions and packaging information, DC, AC parameters and applications can better help us write test programs, especially pin descriptions and packaging. Information, this part is related to resource allocation and device interface board design. The picture below is a sample test specification.
After understanding the product manual and testing Spac, it is time to start developing the test program. The test program tests the DUT according to Spac. During the test process, the program controls the system hardware, applies excitation, measures the response, and sets the threshold according to expectations. Compare and finally give Pass or Fail for each test item. The test program will also classify the DUT according to the test results of the DUT in the test. This process is called "Binning" or "Binning". NI's test programs are generally written using LabView, but there are currently many programs written in C#. The written test programs will be placed in the program management software TestStand, and then mass production test programs can be made. I believe many friends are familiar with LabVIEW. LabVIEW is widely used in the field of instrument control. You may not be particularly familiar with TestStand. The use of these two software will be introduced in detail later.
When doing mass production testing, the order in which the test procedures are executed is very important. The following is the recommended order.
1) Open and short circuit testing should be the first priority. Because once the DUT is short-circuited and faulty, other subsequent test results are meaningless.
2) Projects with more failures should be executed this morning.
3) For different application environments, define products with different speed levels or multiple Pass levels, which can improve product yield.
4) Test data should be checked regularly to optimize the test process.
The following is a schematic diagram of the running sequence and bins of the test project.
Regarding partitioning, many people may not understand it very well at first. Generally speaking, Bin is divided into two types: hardware Bin and software Bin.
Hardware Bin is the actual physical operation of the product, which means that the DUT for the test Pass should be placed in a tray of the Pass by the robot, and the DUT for the Fail should be placed in the Fail tray. Of course, there can also be more hardware Bins here, which mainly depends on the parameters of the sorter or probe station connected to the ATE.
Software Bin is limited by the limitations of the ATE system software, so the number of general software Bins that can be defined can be large. It is mainly used to analyze product failure in more detail, which is equivalent to labeling different performances of the DUT.
Next, I will start with the software I use, so stay tuned!