The seminar presented by Mr. Abdul Munaff covered surface mount technology (SMT), comparing it to traditional through-hole technology and highlighting its advantages such as miniaturization and cost-effectiveness. Key topics included the basic SMT process flow, equipment used, and the importance of understanding electrostatic discharge and the Restriction of Hazardous Substances (RoHS) directive. The seminar aimed to inspire creativity, facilitate knowledge transfer, and raise awareness about modern electronics assembly techniques.
SMT Overview
SurfaceMount Technology (SMT) refers to a specific type of
electronics assembly where electronic components are attached to the
surface of a substrate (typically a printed circuit board).
SMT is a modern alternative to traditional thru-hole technology where
components are attached to substrates by leads that passed through
holes in the PCB.
Surface Mount components require less space so SMT is helpful in
product miniaturization.
Miniaturization means – The process of making something very small
using Modern Technology
7.
Surface Mount VsThru Hole
Double-Sided Surface Mount
Through-hole Technology
Load BarePCB:
Basic SMT process flow
PCB
Surface Mount Pad
Surface Mount Pad
Through hole Pa
1
Typical PCB
insulated substrate
copper connections
protective covering
10.
Solder PastePrint: A stencil printer is used to print solder paste
onto PCB.
PCB
Stencil frame
Stencil
Squeegee Solder
Paste
Snap-off
The main reason for printing solder paste onto the PCB is
to supply solder alloy for the solder joints.
Solder Paste
12.
Place SurfaceMount Components: One or more pick and place
or “chip shooter” machines are used to accurately place SMT
components onto PCB.
SMT
Component
Lead
Pick and Place
Machine Nozzle
15.
Reflow: Areflow oven heats the PCB to a temperature that melts
the solder alloy.
Solder
Joint
Fillet
16.
Cleaning: ThePCB is cleaned of flux residues if necessary.
17.
Equipments used SMTAssembly
SOLDER PASTE
STENCIL
PRINTER
PICK N PLACE/CHIP SHOOTER
REFLOW OVEN
Why Use SurfaceMount Technology?
Miniaturization of Products.
SMD’s have improved performance over through-hole
components due to their smaller size, shorter internal leads and smaller
board layouts.
SMDs can be more cost effective than traditional through-hole
components due to the smaller board size, fewer board layers and
fewer holes.
Smaller component size: Typical size (1206 - 0.12" × 0.06" ).
Faster assembly: Some placement machines are capable of placing
more than 1,36,000 components per hour.
Types of SMD’s
27.
Main disadvantages
The manufacturingprocesses for SMT are much more sophisticated
than through-hole, raising the initial cost and time of setting up of
production.
Manual prototype assembly or component-level repair is more
difficult.
SMDs cannot be used directly with breadboards.
ELECTROSTATIC
DISCHARGE
Electrostatic discharge (ESD)is the sudden
flow of electricity between two electrically
charged objects caused by contact, an electrical
short, or dielectric breakdown.
The ESD occurs when differently-charged
objects are brought close together or when the
dielectric between them breaks down, often
creating a visible spark.
Restriction of HazardousSubstances
(RoHS The Restriction of Hazardous Substances Directive 2002/95/EC,
(RoHS), short for Directive on the restriction of the use of certain
hazardous substances in electrical and electronic equipment, was
adopted in February 2003 by the European Union.
This directive restricts (with exceptions) the use of six hazardous
materials in the manufacture of various types of electronic and
electrical equipment.
It is closely linked with the Waste Electrical and Electronic
Equipment Directive (WEEE), which sets collection, recycling and
recovery targets for electrical goods and is part of a legislative
initiative to solve the problem of huge amounts of toxic electronic
waste.