Mobile phones are one of the most essential things nowadays. Also, it has become costly device among some other electronic devices. As mobile phones have numerous precious components and chips inside of it, so top-notch precautions are taken when manufacturing them. Some of the most popular mobile phone manufacturers are Apple, Samsung, HTC, BlackBerry, Sony Ericsson, Google, Huawei, Motorola, OnePlus, Nokia, vivo, Xiaomi and so on. Now there are two categories of building a mobile phone. One is manufacturing the devices/components and the other is assembling the devices. In this article, we’re going to talk about the second one which is the assembling factory.
Mobile phone manufacturing factories are one of the safest where factory workers or engineers take maximum precaution at every step. From tiny safety precaution to giant measurements, every single thing is brought under concern. Some of the things will be hard to believe if not worked in a phone manufacturing factory. So, let’s break the barrier and get into it.
Building: There are hundreds of hundreds of mobile phone manufacturing facilities around the world. Every one of them is highly safe from all electrical hazards and other issues. First of all, let’s talk about the building or structure. The building is not a regular building where devices gets assembled, during the design of the building several things comes under concern, so that in case of any emergency, it doesn’t affect the inside process at all. In addition to that, all the high-standard electrical safety parameters are strictly followed so that no single incident occurs. Every single electrical bus is connected to sufficient amount of surge protectors so that any incoming spike is suppressed without letting the system know. It also helps against lighting during thunderstorms just because enough lightning arrestors are connected. Also, there are plenty of CB (Circuit Breaker) connected to every device inside the factory.
How to enter into production floor: There are several compartments in a building such as Admin, Management, Production, Warehouse, and SMT. Among them, Production and SMT are the great concern of all. Hence, assembly process gets done in these floors. Let’s talk about the production floor first.
If an employee needs to enter the production premises then she/he must follow some mandatory steps before entering into the facility. The first one is, suiting up. In this part, the employee must have to wear an ESD suit, ESD pants, ESD cap, and ESD slipper so that the static charge is stored inside a human body and doesn’t affect any devices/operation going inside the production floor.
Then the employee must go through a couple of scans such as Metal scanning, magnetic field scans, x-ray scans, and so on. Enforced security personnel check the body several times so that there are very minimum tolerances. It should be kept in mind that, nobody can enter the floor with a metal, whatever it is, it could be a metal chain or pen these aren’t allowed as well. It is prohibited to put off the cap/suit/pant/slipper inside the production floor.
Inside the factory: A big giant central air conditioning system is installed to maintain proper air circulation. Usually, inside a mobile phone factory, there are tons of electronic materials, semiconductor devices, and A-class materials i.e.: Liquid Crystal Module, Camera Sensor, Main Board, Mainboard upper cover, and Battery cover stored in the material room. These devices/components are very much reactive to static electricity, temperature and humidity. So, these parameters are controlled in such a way so that it doesn’t get affected by the company itself. Below ambient temperature, around 17-23 degrees Celsius is followed and humidity is maintained in between 40% to 60%.
Because too much humid air will start corrosion and devices/components will be affected. Too dry air will create static electricity in the system. With every electrical system or giant calibrating or testing machine there are 3 indicator lights. They are Green, Yellow, and Red. In normal conditions when the system is working perfectly the green keeps glowing, when there is some technical issue or the machine is not working then it turns on the siren along with a Red bulb. And when it is under maintenance then the yellow one glows.
ESD Safety: ESD stands for Electro-static Discharge. Inside the factory, some very important parameters are brought under great concern. One of them is ESD. Every single electronic device inside the factory is connected to the main ESD bus and the bus is connected to the earthing of the building. This means every single of them are practically earthed and it means everything. From chairs, tables, and trolleys to giant electrical equipment.
Alongside, the floor is divided into two major parts. One of them is the normal area another one is the ESD area. The floor tape is attached to indicate which one is an ESD area and which one is a non-ESD area. Only authorized personnel are allowed to enter the ESD area.
Working stations and devices: For one specific device model there are dedicated assembly lines, these are also called Online Process Lines. The operator works on workstations. Every workstation is covered by ESD table mat and these mats are made of electron non-conductive material. Every station has one or more electrical devices which are electrically earthed plus the chair and table too. The most amazing thing is the person who is working on the working station is electrically earthed by a wristband. During working time, none is allowed to take off those wristbands. These are also known as ESD bands. Now the most interesting part is every station has one fan named De-ionizing fan or people also call it ION fan.
What do these fans do even after central air-conditioning system?
This De-ionizing fan ensures that the air doesn’t get ionized and harms the components/semi-assembled devices. Interesting, right? There are a lot of computers along with mice and keyboards. These things are also covered with foil tin paper and connected to ESD.
Backup power supply: Power cut usually occurs in such countries but factories runs 24x7. Even though the incoming power is not coming from the national grid where mass consumers are connected. They must have a dedicated sub-station inside the premises.
There are some dedicated industrial lines whose powers usually never get cut off, if a power cut occurs then what happens? Yes, they have backup plans, usually, factories have big giant backup generators/dynamos, and ATS (Automatic Transfer Switch) is connected so in the seconds the power gets cut from the national grid the captive generators can continue supplying power without any unexpected delay. That makes it an uninterrupted supply, indeed.
How to get out of the premises: Simple! How did you enter the premises that is the only way out. Like all the scans and tests you have to pass to get to the main entrance. None can take a single tiny piece of metal from the factory, it is highly secured and all the precautions are taken in such a way. As I have personal work experience in a mobile phone manufacturing factory so it was a great opportunity to learn about that place. Hope this will help you learning about the safety featury of a mobile phone assembly factory. In some days, we’ll try to talk about “How they make a mobile phone device in detail!”, till then stay safe, and stay blessed.