Surface Mount 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. SMT Overview SMT V/S THROUGH HOLE Basic SMT process flow Equipments used SMT Assembly Through Hole Assembly & Soldering ELECTROSTATIC DISCHARGE RoHS

1. A Seminar on
PRESENTED BY:
Mr. ABDUL MUNAFF
Asst. Professor
DEPARTMENT OF ELECTICAL & ELECTRONICS
ENGINEERING, SIET, VIJAYAPURA.

2. Surface Mount Technology

3. Surface Mount Device (SMD)

4. ORGANIZATION OF PRESENTATION
 Objective of this Seminar
 SMT Overview
 SMT V/S THROUGH HOLE
 Basic SMT process flow
 Equipments used SMT Assembly
 Through Hole Assembly & Soldering
 ELECTROSTATIC DISCHARGE
 RoHS
 Outcome

5. Objective of this Seminar
 INSPIRING CREATIVE & INNOVATIVE MINDS
 KT (Knowledge Transfer)
 Technology Awareness
 yh

6. SMT Overview
 Surface Mount 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 Vs Thru Hole
Double-Sided Surface Mount
Through-hole Technology

8. Basic SMT process flow

9.  Load Bare PCB:
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 Paste Print: 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 Surface Mount 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: A reflow oven heats the PCB to a temperature that melts
the solder alloy.
Solder
Joint
Fillet

16.  Cleaning: The PCB is cleaned of flux residues if necessary.

17. Equipments used SMT Assembly
SOLDER PASTE
STENCIL
PRINTER
PICK N PLACE/CHIP SHOOTER
REFLOW OVEN

18. SOLDER
PASTE

19. STENCI
L
Polyester Mesh
Stencil Frame
Metal Foil
Epoxy
Aperture

20. STENCI
L

21. SOLDER PASTE PRINTER

22. CHIP SHOOTER/PICK n PLACE
MACHINE

23. REFLOW
OVEN

24. REFLOW
OVEN

25. REFLOW
OVEN

26. Why Use Surface Mount 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 manufacturing processes 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.

28. THROUGH HOLE

29. WAVE SOLDERING

30. WAVE SOLDERING

31. 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.

32. ELECTROSTATIC
DISCHARGE

33. Restriction of Hazardous Substances
(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.

34. Restriction of Hazardous Substances (RoHS)
Lead (Pb): < 1000 ppm
Mercury (Hg): < 100 ppm
Cadmium (Cd): < 100 ppm
Hexavalent Chromium: (Cr6+)) < 1000 ppm
Polybrominated Biphenyls (PBB): < 1000 ppm
Polybrominated Diphenyl Ethers (PBDE): < 1000 ppm
Bis(2-Ethylhexyl) phthalate (DEHP): < 1000 ppm
Benzyl Butyl Phthalate (BBP): < 1000 ppm
Dibutyl Phthalate (DBP): < 1000 ppm
Diisobutyl Phthalate (DIBP): < 1000 ppm

35. OUTCOME
 Identify Surface Mount Devices and Through Hole Devices.
 Usage of Presentation Tools.
 Electro Static Discharge (ESD)
 Handling PCBA’s
 Information on RoHS

36. Queries Session
 This is just an introduction to the Surface Mount Technology, It
doesn't end here – It’s a beginning.
 To be continued……

38. Outcome based Education
ASK – Attitude, Skill & Knowledge