Introduction

Dry storage cabinet /Dehumidifier is a smart drying and solution for storing provisions for PCBS. Components classified as an MSD (Moisture sensitive devices) are stored in dry storage cabinets. These devices are most susceptible to moisture related defects. The increased process temperatures along with the transition to lead-free soldering create a threat to components and PCBs. The moisture inside the electronic components entering the SMD Reflow Soldering Ovens, evaporates suddenly at high temperatures and attempts to escape from the component with pressure and causes malfunctions such as cracking, swelling, delamination and popcorn effect. The metal cabinets feature tightly sealed doors and multiple shelves for storing trays and reels for extended periods of time. Humidity is removed from the cabinets by use of a powerful desiccant. Moisture absorbed by the desiccant is vaporized and released outside the dry box. Digital controls record the temperature and humidity over time. They use a constant positive pressure flow to void the cabinet of all oxygen, which forces out all moisture and contamination. Moisture absorbent materials including electronic components, circuit boards, nano fibers, contact lenses, laboratory samples and other vulnerable materials are kept dry and free from water ingress. The dehumidification to less than 0.5% RH means that they can safely remove moisture, thus resetting floor life without oxidation, even at ambient temperatures. The primary requisite of maintaining the physical conditions of the cabinet is monitored and balanced by developing sensors.

Background

Dry Cabinet is with an ESD painted steel body which does not require any maintenance having a lifespan of more than 10 years. It consists of two powerful dry units and a humidity alarm buzzer / humidity alarm light which will sound or flash if the humidity exceeds set value.

It is a storage device that allows you to protect a wide range of products against humidity problems. A Desiccant Dry Cabinet is an enclosure with a supply of desiccant which maintains an internal environment of 1-50% RH. Desiccant dry cabinets are also called: desiccators, dry boxes, dehumidifying cabinets, and ultra low humidity storage cabinets. Humidity, temperature, and alarm functions are shown and can be adjusted by digital control panel. Key Lock function on the digital control panel prevents unintended changes of setting. Sensor calibration function is also available with a digital panel. For instance, if the inside humidity of the cabinet is 12%Rh and the cabinet is set to go down to 5%Rh. If the sensor has an accuracy of ±5% then the dehumidifying process will stop at a point between 10%Rh and 5%Rh thinking that it has reached its goal which would lead to incorrect calibrations. This has to be replaced with smart sensor devices of greater accuracy for humidity and temperature in a perfectly calibrated condition.

Project Objectives

This project aims to use the Rapid IoT devices to create a smart dry storage cabinet system that intelligently helps in maintaining a low relative humidity (RH) as required by the IPC standard J-STD-033 while preventing electrostatic discharge (ESD) and tracking the ambient temperature, humidity, and the air quality of a cabinet. The cabinet monitor device will help the users to track the metrics related to their equipment storage and have in their mobile device all the information in the forms of a dashboard, helping them to take decisions about controlling the respective parameters in order to maintain the required environment.
The Rapid IoT device is connected and powered through the RaspberryPi (via USB) and provides the measurements via Bluetooth. The RaspberryPi is connected to the router to provide WiFi access to the dashboard.
Design automated control systems that allow electronic manufacturers to manage and track their MSD devices. They use automatic data collection technology, such as bar coding and radio frequency identification. The automated systems eliminate the need for manual procedures, such as identifying MSDs, filling out log sheets and entering time calculations, which are time-consuming and open to human error.
Each drying cabinet is equipped with a very accurate sensor where each sensor is factory calibrated and comes with a calibration protocol.

Benefits

Allow electronic manufacturers to manage and track their MSD devices.

A cloud based infrastructure integrating both cost-saving feature and reliability.

Extremely convenient and user friendly since these devices are amalgamated to users mobile devices which allows them to easily access from anywhere.

All parameters related to dehumidification can be adjusted and monitored on the touch screen control panel.

When the desiccant units are saturated with moisture, they can regenerate themselves without any user intervention, and only when they need to regenerate, in this way they can prepare themselves for the next drying process.

Extends the life of PCBs.

Accurate monitoring systems allowing onsite calibrations.

Prevents time loss, cost loss, and failures.