Manufacturing

The semiconductor device fabrication  is the process used to create the integrated circuits, including the microcontroller. It is a multiple-step sequence of photolithographic and chemical processing steps during which electronic circuits are gradually created on a wafer made of pure semiconducting material, Silicon is almost always used, but also used gallium arsenide. 

Wafer

Actually the manufacturing process of large scale integration VLSI follows the method (Very Large Scale Integration) using Silicon as raw material.

Microprocessor manufacturing facilities.

General steps of making a silicon Integrated Circuit:

• Wafer preparation, the starting material for the manufacture of circuits is the high purity silicon, with which is created a cylinder that is then sliced​​. Later is polished for better electrical and mechanical properties.

• Oxidation, is the process which form silicon dioxide (SiO2) on the wafer to create a thin film, transparent and highly reflective surface.

• Diffusion, is a method in which impurity atoms are introduced into the silicon to change its resistivity, the most common impurities are boron, phosphorus and arsenic.

• Ion Implantation, it is another method used to introduce impurities into the semiconductor crystal.

• Deposition by chemical vapor, is a process which leads to the formation of solids in a substrate by chemical reactions of gases, which serves as thermal insulation.

• Metallization, is the process that interconnect the various components forming the integrated circuit (transistors, condesandores, etc.), depositing a metal on the silicon surface.

• Photolithography, is the technique used to define the geometry of the surface of the components of an integrated circuit.

• Packed,  a wafer can contain hundreds of circuits, they are separated and are then mounted in capsules, are  connected by gold wires, and the package is then sealed with plastic.

Many toxic materials are used in the fabrication process such as arsenic, antimony,  phosphorus,  arsine, phosphine, and  silane,; and highly reactive liquids such as hydrogen peroxide, fuming nitric acid, sulfuric acid, and hydrofluoric acid. It is vital that workers not be directly exposed to these dangerous substances.

Industrial design

The most important standard industrial design in the microcontroller  is high efficiency because higher speed of operation this can  achieve optimize processes (internal tasks of a device, appliance, etc.).

This depends on the internal structure of the microcontroller, a smaller component (logic gates) more speed.

Evolution

Intel 4004

The first microcontroller was developed by a small company called Intel (initials of Integrated Electronics ) in the 1970s, with the objective of create and market chipset the general purpose. The 4-bits Intel 4004 and Intel 8008 released in 1971, were single-chip microprocessor, both processors required external chips to implement a working system, which makes them very expensive and not very functional.

Other source say that the firsts in developed a chipset were the engineers of TI (initials of Texas Instruments ) Gary Boone and Michael Cochran, they created in 1971 the TMS 1000 a microcontroller that  basically had  read-only memory, read/write memory, processor and clock on one chip.

TMS 1000

Later Intel developed the Intel 8048 y the Intel 8051 introduced in the year of 1976, of the witch sold more of thousand millions of devices, were used in the keyboards of the computers of IBM. Actually variations  of 8051 are still sold, being the most long-lived electronic design history.

Intel 8051

During the 1990s, microcontrollers with electrically erasable and programmable ROM (EEPROM) memories, such as flash memory. Before reprogrammable electrical devices was necessary programming skills, which is complex and a limitation. Today enough with a electrical signal for erase and program a chipset.

Nowadays has besides of general purpose devices, specialized microcontrollers are being produced for areas such as automotive, lighting, communications and low-power consumer devices. In 2010 was created the flash Atmel microcontroller which has a size of 2 mm x 2 mm, sufficient to control a toy

Atmel flash

Introduction

Microcontroller 

What kind of product is it?

A microcontroller is a integrated circuit  able to execute the orders recorded in its memory, is composed of three functional units: processor core, memory, and programmable input/output peripherals. In conclusion it is a small computer.

What is an useful product? What do you use it for?

The microcontrollers are found in many places today, they are all small computers functionals are used in automatically controlled products, devices and appliances as  oven microwave oven, washing machine, TV, stereo, MP3 player, etc.

Some advantages and disadvantages about the product

Some advantages are:

• Many applications.
• They are inexpensive and small.
• Easy handling.
• Low power consumption.
• Increased processing speed.

The main disadvantage with microcontrollers is the  electronic resources are limited as memory and heap.

The microcontroller components