The industrial electronics manufacturing process for the electronic assemblies found in many of today's electronic devices, is a multi-step process.

Component and PCB manufacturing

Components such as resistor

Resistor

A linear resistor is a linear, passive two-terminal electrical component that implements electrical resistance as a circuit element.The current through a resistor is in direct proportion to the voltage across the resistor's terminals. Thus, the ratio of the voltage applied across a resistor's...

s, capacitor

Capacitor

A capacitor is a passive two-terminal electrical component used to store energy in an electric field. The forms of practical capacitors vary widely, but all contain at least two electrical conductors separated by a dielectric ; for example, one common construction consists of metal foils separated...

s and integrated circuit

Integrated circuit

An integrated circuit or monolithic integrated circuit is an electronic circuit manufactured by the patterned diffusion of trace elements into the surface of a thin substrate of semiconductor material...

s are generally made by specialized contractors. Integrated circuits are generally made by the process of photolithography

Photolithography

Photolithography is a process used in microfabrication to selectively remove parts of a thin film or the bulk of a substrate. It uses light to transfer a geometric pattern from a photomask to a light-sensitive chemical "photoresist", or simply "resist," on the substrate...

.

Printed circuit board

Printed circuit board

A printed circuit board, or PCB, is used to mechanically support and electrically connect electronic components using conductive pathways, tracks or signal traces etched from copper sheets laminated onto a non-conductive substrate. It is also referred to as printed wiring board or etched wiring...

s (PCBs) are usually manufactured by specialized contractors.

Mounting surface-mount components

Surface-mount components can be hand-soldered

Soldering

Soldering is a process in which two or more metal items are joined together by melting and flowing a filler metal into the joint, the filler metal having a lower melting point than the workpiece...

, but usually they are mounted using surface-mount technology

Surface-mount technology

Surface mount technology is a method for constructing electronic circuits in which the components are mounted directly onto the surface of printed circuit boards . An electronic device so made is called a surface mount device...

. The process usually consists of three steps:

1. A solder paste
   Solder paste
   Solder paste sometimes refers to soldering flux that does not contain solder.Solder paste is used to connect the leads of integrated chip packages to attachment points in the circuit patterns on a printed circuit board...
   
    is printed where the components need to make a connection with the PCB tracks
2. Components are placed using a pick and place machine
   SMT Placement Equipment
   SMT component placement systems, commonly called pick-and-place machines or P&Ps, are robotic machines which are used to place surface-mount devices onto a printed circuit board...
   
   
3. The PCB passes through a reflow oven
   Reflow oven
   A reflow oven is a machine used primarily for reflow soldering of surface mount electronic components to printed circuit boards .- Infrared and convection ovens :...
   
   

The process is repeated twice in order to populate both sides of the PCB.

Mounting through-hole components

Through-hole

Through-hole technology

Through-hole technology, also spelled "thru-hole", refers to the mounting scheme used for electronic components that involves the use of leads on the components that are inserted into holes drilled in printed circuit boards and soldered to pads on the opposite side either by manual assembly by...

 components and connectors

Electrical connector

An electrical connector is an electro-mechanical device for joining electrical circuits as an interface using a mechanical assembly. The connection may be temporary, as for portable equipment, require a tool for assembly and removal, or serve as a permanent electrical joint between two wires or...

 can be hand-soldered, but usually they are mounted using wave soldering

Wave soldering

Wave soldering is a large-scale soldering process by which electronic components are soldered to a printed circuit board to form an electronic assembly. The name is derived from the use of waves of molten solder to attach metal components to the PCB...

 or selective soldering

Selective soldering

Selective soldering is the process of selectively soldering components to printed circuit boards, molded modules, etc. that could be damaged by the heat of a reflow oven in a traditional SMT assembly process. Consequently this process usually follows an SMT oven reflow process, but not always...

 techniques.

Depanel

In order to increase manufacturing capacity, PCBs are often designed so that they consist of many smaller individual PCBs that will be used in the final product. This PCB cluster is called a panel or multiblock. The large panel is depanel

Depanel

Depaneling is a process step in high-volume electronics assembly production. In order to increase the throughput of printed circuit board manufacturing and surface mount lines, PCBs are often designed so that they consist of many smaller individual PCBs that will be used in the final product....

ed at some stage in the process.

Cleaning and drying

A completed assembly needs to be cleaned. Various techniques are used depending on what type of solder and flux was used. A cleaned assembly needs to be dried before any power can be applied.

Case-up

The case-up process consists of one or more of the following:

• Adding a conformal coating
  Conformal coating
  Conformal coating material is applied to electronic circuitry to act as protection against moisture, dust, chemicals, and temperature extremes that, if uncoated , could result in damage or failure of the electronics to function...
  
   or potting
  Potting (electronics)
  In electronics, potting is a process of filling a complete electronic assembly with a solid or gelatinous compound for resistance to shock and vibration, and for exclusion of moisture and corrosive agents...
  
  
• Final mounting of the depaneled PCB in an enclosure
  Enclosure (electrical)
  An electrical enclosure is a cabinet for electrical or electronic equipment to mount switches, knobs and displays and to prevent electrical shock to equipment users and protect the contents from the environment...
  
   using various methods: screwing etc.

Testing

Electronic assemblies are tested at various process steps using the following methods:

• In-circuit test
  In-circuit test
  In-circuit test is an example of white box testing where an electrical probe tests a populated printed circuit board , checking for shorts, opens, resistance, capacitance, and other basic quantities which will show whether the assembly was correctly fabricated...
  
  ing of integrated circuits and other components
• Inspection
  Inspection
  An inspection is, most generally, an organized examination or formal evaluation exercise. In engineering activities inspection involves the measurements, tests, and gauges applied to certain characteristics in regard to an object or activity...
  
   of components and joint quality, using simple visual inspection, X-Ray
  X-ray
  X-radiation is a form of electromagnetic radiation. X-rays have a wavelength in the range of 0.01 to 10 nanometers, corresponding to frequencies in the range 30 petahertz to 30 exahertz and energies in the range 120 eV to 120 keV. They are shorter in wavelength than UV rays and longer than gamma...
  
   inspection (usually of invisible joints, e.g. BGA
  BGA
  BGA can refer to:* Bach-Gesellschaft Ausgabe, the first complete edition of the works of J.S. Bach* Ball Grid Array, a type of surface-mount packaging used for integrated circuits* Battle Ground Academy, a private school in Franklin, Tennessee, USA...
  
  ), and/or automated optical inspection
  Automated optical inspection
  Automated optical inspection is an automated visual inspection of a wide range of products, such as printed circuit boards , LCDs, transistors, automotive parts, lids and labels on product packages or agricultural products...
  
  
• Final functional test after case-up
• Various other tests for assembly functioning in a range of conditions (temperature, humidity, vibration, strain, etc.)

Variations

Sometimes, when only one or two finished devices will be needed, they are put together using one of the more durable electronics prototyping techniques.