ELECTRONICS MANUFACTURING

This article presents a typical manufacturing process of an electronic assembly.

Contents

Component manufacturing

Printed circuit board manufacturing

Surface-mount device components mounting

Through-hole components mounting

Depanel

Case-up

Cleaning

Drying

Testing

Component manufacturing

Components such as resistors, capacitors and integrated circuits are generally made by specialized contractors. Integrated circuits are generally made by the process of photolithography

Printed circuit board manufacturing

Printed circuit boards (PCBs) are usually manufactured by specialized contractors.

Surface-mount device components mounting

Surface-mount device (SMD) components can be hand-soldered, but usually they are placed using surface-mount technology (SMT). The process usually consists of 3 steps:
#solder paste print
#SMT placement, using a "pick and place" machine
#reflow oven
The process is repeated twice in order to populate both sides of the PCB.

Through-hole components mounting

There are 3 methods for mounting through-hole components and connectors:

★ hand soldering

★ wave soldering

★ selective soldering

Depanel

In order to increase PCB and SMT capacity, several boards are panelized into one large multiblock. They are depaneled at a certain stage in the process, which might be before SMT, after SMT or just before final case-up.

Case-up

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

★ conformal coat

★ potting

★ final case-up of the depaneled PCB in a housing using various methods: screwing etc.

Cleaning

A completed PCA needs to be "cleaned", using various techniques depending on what type of solder and flux was used.

Drying

A clean wet board needs to be "dried" before the power can be inspected or electrically activate.

Testing

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

★ In-Circuit Testing (In circuit test) of integrated circuits and other components

★ inspection of components and joint quality:
:
★ visual inspection
:
★ X-Ray inspection (usually of invisible joints, e.g. BGA)
:
★ Automated Optical Inspection Corporation]

★ Final functional test after case-up

★ various other tests for assembly functioning in a range of conditions (temperature, humidity, vibrations, strain, etc.)