Design Of Testing Equipment For Semiconductor Devices Using MSP430

Power semiconductor devices are the main components in the electronics technology. A billion of semiconductors have been fabricated after the invention of Thyristor in 1956. Power semiconductors have so many applications in daily life or you can say that there is no electronic device that is without it. Now day’s semiconductors devices like BJTs, MOSFETs, IGBTs and IGCT are the most dominant devices in the electronics industry. They are used for high voltage, fast switching and high frequency etc. The SiC material helps to improve a lot of parameters of semiconductor devices over Si material.As semiconductor is the important part of every electronic device. Most of the times, the electronics device is not working properly due to the damage of semiconductor device or some other reason. If it will be due to the semiconductor device and you have to change it. As there are a lot of semiconductor devices and if you know the model no then it will be easy for you to change it. If you don’t have any data about semiconductor device then it will be big trouble for you. For this purpose we designed a semiconductor testing device.For measuring the semiconductor, we used two switches. One switch is used to separate the pull up resistor of the microcontroller. We can off the output of the pin by using another switch. The output depends on first switch and it is also used to control the pull up resistors. The states of both switches can’t be changed at the same time but one after the other. The three testing terminal of the semiconductors device is connected with three pins of the microcontroller. The states of every testing terminal can be changed to output and in the same way it is connected with ground of power supply. In another way, they are connected with 680 k or 470 k via ground or power supply. This method is used for positive pin. The same criteria are used for negative state of testing terminal. The third terminal pin which is also called the test pin can be open or can be connected same like positive and negative pin. This device consists of two parts that are hardware and software part. In hardware part, we designed a PCB board. We selected Altium Designer Software for schematic diagram as well as for PCB design. First of all, I draw the schematic diagram for my project, and make confirm all of its connection by simulation. After confirming all connection, I move to PCB design. In PCB design, I made the connection in such a way that will not affect the other components. I try my best of avoid all issues like heat and electromagnetic. I used 16x2 LCD in my project. LCD screen is electronic device which is used in many applications.LCD has some advantage over segment display like economical, easily programmable, animation and so on. A 16x2 LCD means that it can display 16 characters per line and there are two lines like this. Each character in both lines consists of 5x7 pixel matrix. Most of the libraries for schematic diagram and PCB design, I designed by myself. There are a lot of microcontrollers in the market but we chose MSP430F2132 as it is low power MCU. Other properties include mixed signal processing, 16 bit processor, 16-bit address and data buses; 32 KHz CPU, wide range of peripherals, and restart quickly due to DCO etc. The 9V battery is enough for running this device. I used two voltage regulators in my project. One regulator(LM7805) is used for converting 9v to 5v. All components except MSP430 need 5v for working. Other regulator(AM1117) is used for converting 5v to 3v. This is especially for MSP430 as it just needs 3v. If we will give power to MSP430 more than 3 v then it will damage. The soldering was done in the Lab. The size of PCB board was 800mmX500 mm. The more detail about hardware part is explain in later chapter. In software part, the main thing is programming and debugging of the MCU. IAR Embedded workbench is suitable development environment for MCU. The programming language that I used is C. We used MSP-FET430 UIF for interface with PC. It is strong emulation tool that quickly start the development of the application on the MSP430 microcontroller. It consists of USB debugging tool that is used for the programming and debug of MSP430 in system with the help of JTAG interface or with the help of Spy Bi-Wire protocol. By using it, we can erase the flash memory and programme new code within seconds. There is no need to supply external voltage as MSP430 is low power device. We can’t use any other USB interface as it is not compatible with MSP430. After completing of both part, we have some functionality test to make it sure that there is no any problem in the PCB board. These tests consist of I/O functionality test, oscillator test and peripheral test. In I/O functionality test, we check all pins by sending some simple code. This series of test is to check the connectivity of all the pins and also ensure there is no cross connection between two or more pins on the board. In oscillator test, a simple code is written to enable and disable usage of external crystal oscillator. In peripheral test, code used to activate the peripheral and test. These codes come from code sample of MSP430. After testing, the board is ready for measurement.It will automatically identify the NPN and PNP transistor, calculate the current amplification factor and base emitter threshold voltage and show it on LCD screen. In the same way, it also identifies N-channel and P-channel MOSFET, calculate gate threshold voltage and gate capacity. The shutdown current is about 20 nA.