Automateing The Cryoprob By Raspberry PI(RPi)

Abstract

Cryoprobes are probes of Cryogenic probe station. Cryogenic probe stations are high performance instruments, which are used for creating environment for testing devices and semiconductor wafers. Cryogenic probe station can create affordable vacuum, temperature and cryogenic probing of wafer and devices. To reduce human efforts and prevent human error, it is required to automate this instrument. An embedded system is necessary for automating this instrument, which can facilities flexibility to analyze the working and performance of devices and semiconductor wafers.

To full fill that purpose, it requires an automation and control system. To achieve this objective, we use Raspberry Pi (RPi) Board provided by Raspberry pi foundation. RPi is based on "SoC"(System on Chip) concept. It is a small size CPU, able to provide interactive services to the user. RPi used Broadcom BCM2835 chip. BCM2835 contains ARM1176JZFS and Graphical processor unit (GPU). RPi is very small in size, its cost is low and it provides high performance. RPi also support different operating systems. Most efficient operating system for RPi is Raspbian "wheezy". Rasbian is a customized version of the Debian OS for RPi.

Combination of Raspbian OS and RPi makes it possible to use python language to create interactive applications as per benchmarking of RPi GPIO. According to benchmarking one can achieve 44 KHz of frequency which is enough for automation and Python language provides Application Peripheral Interface (API) to control GPIO and create Graphical User Interface (GUI).

These interactive applications provide the user an easy control on Croprobes. Cryoprobes require a high resolution motion control to keep on tracing all the motion of every probe and keep that data for future analysis. And also one can access it from remote distance. In this hardware control system we also require temperature measurement system for every probe to create graph between time and temperature.

This application also provides service to store data which occurs during practical, for future analysis. In automation, through stepper motor with 1.8 degree of step angle, 98% accuracy is achieved.

To achieve remote access shell script is used. Performing text processing and file operation remote access task is achieved. This application also provides service to store data which occurs during practical, for future analysis. In automation, through stepper motor with 1.8 degree of step angle, 98% accuracy is achieved. To achieve remote access shell script is used. Performing text processing and operation remote access task is achieve.