autopal training report

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CHAPTER 1

COMPANY PROFILE

1.1 INTRODUCTION

Autopal group, a 40 years old enterprise with excellence and pioneer-ship in many engineering and

lighting products. Embedded with many international acclaimed quality & product certification the

company has established world-wide marketing network with agents, distributors and customers

across the globe. Autopal was the first company to manufacture the CFL technology in India. It

has continued to shape the group by breaking new grounds & pioneering critical developments in

automotive & lighting industry. The group extends its State-of-Art technology, Avant-garde design

in consumer durable goods like CFL, MHL, domestic use Fan Series. Autopal forays wide products

range of Energy saving lamps CFL, MHL, Down-lighters, LED Series & Tube-light.

Lighting is our business, World is our market”

1.2 HISTORY

Autopal Industries Limited was promoted by Shri Dharam Pal Gupta and his brothers as an energy

saving lighting manufacturing industry. The Company become Public Limited in 15th Oct, 1985

and started it’s commercial production on 27th April, 1992. The Company w as first in India to

manufacture Compact Fluorescent Lamp (CFL) in India with Koren technology and also

manufactured automotive/domestic Halogen lamps & General lighting products.

The unit was established with installed capacity of 12.00 lacs nos. per annum unit of CFL and 30

lakh nos per annum unit of Automotive/Domestic Halogen Lamp. With its substantial investmentand effort in R&D, the company achieved various milstones, in terms of Patents and technology

awards.

1.2 VISION

Innovative and energy conscious solutions are our future. With Autopal’s significant and sustained

development in state of the art lighting technology and globally competitive manufacturing



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operations, supported by award winning product designers sales team and engineers, Autopal

Industries is confident of a progressive and environmentally conscious future.

Fig 1.1 Vision of Autolite (India) Limited

Whether your lighting design challenges are interior, exterior, industrial, and commercial or

architectural, we at Autopal are confident that we have the experience, service locations and design

solutions to meet your every need.

1.3 ACHIVEMENTS

Rajasthan State Export Award in 2010

Vendor Award from Lucas India Service in 2005

EEPC – Export Excellence Award in 2002

ACMA Technology Award in 1998

MARUTI SUZUKI Vendor Performance Award in 1998

ACMA Best Export Performance Award in 1997

State Award for Export Excellence in 1996



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1.6 NETWORK

Fig 1.2 Network of Autolite (India) Limited

Autopal empoers its people to build sturdy & lasting relationship with its business partners,

employees & customers, thus paning the way for continuous growth throughout the nation. Autopal

empowers its people to build sturdy & lasting relationship with its business partners, employees &

customers, thus paning the way for continuous growth throughout the nation

Head Office & Works

Jaipur Address : E-195 (A), RIICO Industrial Area, Mansrovar, Jaipur (Raj) 302020

E-Mail : [email protected] , [email protected]

Branch Office

Branch Address: B-Wing, Office No.1005, Express Zone Building, Western Express Highway

(Dindoshi Flyover) Malad (East), Mumbai-400063

E-Mail: [email protected] , [email protected]

mailto:[email protected]


















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CHAPTER 2

LED

2.1 INTRODUCTION

A light-emitting diode (LED) is a semiconductor light source. LEDs are used as indicator lamps in

many devices and are increasingly used for general lighting. Appearing as practical electronic

components in 1962, early LEDs emitted low-intensity red light, but modern versions are available

across the visible, ultraviolet, and infrared wavelengths, with very high brightness.

When a light-emitting diode is switched on, electrons are able to recombine with holes within the

device, releasing energy in the form of photons. This effect is called electroluminescence, and the

color of the light (corresponding to the energy of the photon) is determined by the energy band gap

of the semiconductor. An LED is often small in area (less than 1 mm2), and integrated optical

components may be used to shape its radiation pattern. LEDs have many advantages over

incandescent light sources including lower energy consumption, longer lifetime, improved

physical robustness, smaller size, and faster switching. However, LEDs powerful enough for room

lighting are relatively expensive, and require more precise current and heat management than

compact fluorescent lamp sources of comparable output.

Light-emitting diodes are used in applications as diverse as aviation lighting, automotive lighting,

advertising, general lighting, and traffic signals. LEDs have allowed new text, video displays, and

sensors to be developed, while their high switching rates are also useful in advanced

communications technology. Infrared LEDs are also used in the remote control units of many

commercial products including televisions, DVD players and other domestic appliances. LEDs are

also used in seven-segment display.

2.2 LED DOWNLIGHTERS

A recessed light or downlight (also pot light in Canadian English, sometimes can light (for canister

light) in American English) is a light fixture that is installed into a hollow opening in a ceiling.



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Fig 2.1 LED Downlighters

When installed it appears to have light shining from a hole in the ceiling, concentrating the light in

a downward direction as a broad floodlight or narrow spotlight. There are two parts to recessed

lights, the trim and housing. The trim is the visible portion of the light. It is the insert that is seen

when looking up into the fixture, and also includes the thin lining around the edge of the light. Thehousing is the fixture itself that is installed inside the ceiling and contains the lamp holder.

TRIM STYLES

Recessed lighting styles have evolved with more manufacturers creating quality trims for a variety

of applications. You can find recessed lighting trim with the standard baffle in black or white,

which is the most popular. They are made to absorb extra light and create a crisp architecturalappearance. There are cone trims which produce a low-brightness aperture. Multipliers are offered

which are designed to control the omni-directional light from "A" style incandescent light bulbs

and compact fluorescents. Lens trim is designed to provide a diffused light and protect the lamp.

Lensed trims are normally found in wet locations.

The luminous trims combine the diffused quality of lensed trim but with an open down light

component. Adjustable trim allows for the adjustment of the light whether it is eyeball style, which

protrudes from the trim or gimbal ring style, which adjusts inside the recess. These lights allow for



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full versatility. Lastly, there are the wall-washer trims, which are designed to eliminate the often

seen "scalloped light effect".

LAMP STYLES

There are two types of lamps for recessed lighting: directional and diffuse. Directional lamps (R,

BR, PAR, MR) contain reflectors that direct and control the light. Diffuse lamps (A, S, PS, G)

control light distribution through their omni-directional light.

2.3 SURFACE LED

Surface Mount LEDs are cost-efficient solutions for low-power, compact designs. The products

come in a variety of available color, lens, and package types and are highly durable.

Surface Mount LEDs are smaller than leaded components, making them ideal for space-limited

board sizes and equipment. They are also highly resistant to shock and vibration and are available

in packages with a considerably higher number of pins than leaded LEDs.

The light weight of Surface Mount LEDs makes them optimal for mobile appliances. They are also

ideally suited for RF applications because of their low levels of parasitic inductance and

capacitance.

2.3.1 FEATURES

Low Power Consumption

Wide Viewing Angle

Variety of Available Colors, Lens and Package Types

High Reliability

Durable



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Fig 2.2 Surface LED

2.3.2 APPLICATIONS

LCD Backlighting

Pushbutton Backlighting

Keypad Backlighting

Automotive Interior Lighting

Symbol Indicators

Front Panel Indicators

Small Message Panel Signage

2.4 LEADED LEDs

Fig 2.3 Leaded LEDs



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Leaded LEDs, also called through-hole LEDs, have for many years played an integral role in

electronic designs. These LEDs are known for their ruggedness, long lifespan, and low power

consumption.

Leaded LEDs are available in a variety of package shapes and sizes and colors.

2.4.1 FEATURES


Highly Reliable

Range of Viewing Angles from Narrow to Wide

Long-Life Solid State Reliability

Rugged Design

Variety of Available Colors, Package Styles

2.4.2 APPLICATIONS

Outdoor LED panels,

Traffic Signals

Automotive Lighting

Instrumentation Indicators

Front Panel Indicators

Small Area Backlighting

2.5 ULTRAVOILET LEDs

Ultraviolet electromagnetic radiation, commonly known as UV, is currently employed in many

industries and applications. The emerging UV LEDs will be an enabling, competitive technology

that drives new and innovative applications. UV-LEDs have a long operating life and are more

environmentally friendly than traditional mercury UV lamps.



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Fig 2.4 Ultraviolet LED

2.5.1 APPLICATIONS

Industrial Curing

Fluorescence disclosing and verification

Air Purification

Medical and Biomedical Applications

Dermatological Equipment

Currency Validation

Forensics Equipment

Photo Polymerization

Spectroscopy

Dental Curing and Teeth Whitening

Sterilization and Medical

DNA Gel



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2.5.2 FEATURES


Low Current Requirement

Tight Tolerance of Wavelengths

Long Life

Environmentally Friendly

Fig 2.5 Electromagnetic Spectrum of LED

2.5.3 WARNINGS AND HANDLING INSTRUCTIONS

UV-LEDs emit invisible ultraviolet radiation when in operation, which may be harmful to eyes or

skin, even for brief periods. Do NOT look directly into the UV-LED during operation. Be sure that

you and all persons in the vicinity wear adequate " UV " Safety protection for eyes and skin. If you

incorporate a UV-LED into a product, be sure to provide WARNING labels.

2.6 FLOOD LIGHT

Floodlights are broad-beamed, high-intensity artificial lights often used to illuminate outdoor

playing fields while an outdoor sports event is being held during low-light conditions.



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Fig 2.6 Flood light in Football Stadium

In the top tiers of many professional sports, it is a requirement for stadiums to have floodlights to

allow games to be scheduled outside daylight hours. Evening or night matches may suit spectators

who have work or other commitment earlier in the day. The main motivation for this is television

marketing, especially in sports such as Gridiron which rely on TV rights money to finance the

sport. Some sports grounds which do not have permanent floodlights installed may make use of

portable temporary ones instead. Many larger floodlights (see bottom picture) will have gantries

for bulb changing and maintenance. These will usually be able to accommodate one or two

engineers.

2.6.1 TYPES OF FLOODLIGHT

The most common type of floodlight is the Metal Halide which emits a bright white light, however

most commonly used for sporting events are high pressure Sodium floodlights which emit a soft

orange light, similar to that of street lights; SON lamps have a very high lumens-to-watt ratio

making them a cost effective choice where certain lux levels have to be met.[citation needed]



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In the recent years there have been new developments and the LED technology has come a long

way and now LED flood lights are bright enough to be used for illumination purposes on large

sport fields.

2.6.2 APPLICATIONS

Cricket

Association football

Rugby League

Racing

Baseball

Tennis



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CHAPTER 3

WORKING OF LED’S

A light emitting diode (LED) is known to be one of the best optoelectronic devices out of the lot.

The device is capable of emitting a fairly narrow bandwidth of visible or invisible light when its

internal diode junction attains a forward electric current or voltage. The visible lights that an LED

emits are usually orange, red, yellow, or green. The invisible light includes the infrared light. The

biggest advantage of this device is its high power to light conversion efficiency. That is, the

efficiency is almost 50 times greater than a simple tungsten lamp. The response time of the LED

is also known to be very fast in the range of 0.1 microseconds when compared with 100

milliseconds for a tungsten lamp. Due to these advantages, the device wide applications as visual

indicators and as dancing light displays.

We know that a P-N junction can connect the absorbed light energy into its proportional electric

current. The same process is reversed here. That is, the P-N junction emits light when energy is

applied on it. This phenomenon is generally called electroluminance, which can be defined as the

emission of light from a semi-conductor under the influence of an electric field. The charge carriers

recombine in a forward P-N junction as the electrons cross from the N-region and recombine with

the holes existing in the P-region. Free electrons are in the conduction band of energy levels, while

holes are in the valence energy band. Thus the energy level of the holes will be lesser than the

energy levels of the electrons. Some part of the energy must be dissipated in order to recombine

the electrons and the holes. This energy is emitted in the form of heat and light.

The electrons dissipate energy in the form of heat for silicon and germanium diodes. But in Galium-

Arsenide-phosphorous (GaAsP) and Galium-phosphorous (GaP) semiconductors, the electrons

dissipate energy by emitting photons. If the semiconductor is translucent, the junction becomes the

source of light as it is emitted, thus becoming a light emitting diode (LED). But when the junction

is reverse biased no light will be produced by the LED, and, on the contrary the device may also

get damaged.

LEDs create light by electroluminescence in a semiconductor material. Electroluminescence is the

phenomenon of a material emitting light when electric current or an electric field is passed throughit - this happens when electrons are sent through the material and fill electron holes. An electron



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hole exists where an atom lacks electrons (negatively charged) and therefore has a positive charge.

Semiconductor materials like germanium or silicon can be "doped" to create and control the

number of electron holes. Doping is the adding of other elements to the semiconductor material to

change its properties. By doping a semiconductor you can make two separate types of

semiconductors in the same crystal. The boundary between the two types is called a p-n junction.

The junction only allows current to pass through it one way, this is why they are used as diodes.

LEDs are made using p-n junctions. As electrons pass through one crystal to the other they fill

electron holes. They emit photons (light).

Fig 3.1 A 5 Watt LED, one of the most powerful LEDs available

Phosphors are used to help filter the light output of the LED. They create a more pure "harsh"

color.

Engineers had to figure out how to control the angle the light escapes the semiconductor, this "light

cone" is very narrow. They figured out how to make light refract or bounce off all surfaces of the

Semiconductor crystal to intensify the light output. This is why LED displays traditionally have

been best viewed from one angle.



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Fig 3.2 A laser also creates light, but through a different construction

Fig 3.3 Phosphors

3.1 LED CHARACTERISTICS

The forward bias Voltage-Current (V-I) curve and the output characteristics curve is shown in the

figure above. The V-I curve is practically applicable in burglar alarms. Forward bias of

approximately 1 volt is needed to give significant forward current. The second figure is used to

represent a radiant power-forward current curve. The output power produced is very small and thus

the efficiency in electrical-to-radiant energy conversion is very less.



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Fig 3.4 LED Characteristics

The figure below shows a series resistor Rseries connected to the LED. Once the forward bias of

the device exceeds, the current will increase at a greater rate in accordance to a small increase in

voltage. This shows that the forward resistance of the device is very low. This shows the

importance of using an external series current limiting resistor. Series resistance is determined by

the following equation.

Rseries = (Vsupply – V)/I

Vsupply – Supply Voltage

V – LED forward bias voltage

I – Current

The commercially used LED’s have a typical voltage drop between 1.5 Volt to 2.5 Volt or current

between 10 to 50 milliamperes. The exact voltage drop depends on the LED current, colour,

tolerance, and so on.

3.2 LED BASICS: HOW TO TELL WHICH LEAD IS POSITIVE OR

NEGATIVE

LED has two leads, one longer than the other,the longer lead is the postive (also known as the

anode) lead.



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If the LED has two leads with leads that are equal in length, you can look at the metal plate inside

the LED. The smaller plate indicates the positive (anode) lead; the larger plate belongs to the

negative (cathode) lead.

Fig 3.5 Surface Mount LED Fig 3.6 LED

LED has a flat area (on the plastic housing), the lead adjacent to the flat area is the negative

(cathode) lead.

It’s a little bit harder to determine the polarity with Surface Mount LEDS. Some are marked with

a (-) to indicate the negative lead, but often, they are not. The single best way to determine the

polarity is through the use a multimeter.

Set the multimeter to the diode/continuity setting. Usually, the multimeter will supply enough

current into the LED which will just barely light it up. The black (common) lead on the multimeter

indicates

3.3 ADVANTAGES & DISADVANTAGES

ADVANTAGES

Energy efficient source of light for short distances and small areas. The typical LED requires

only 30-60 milliwatts to operate



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CHAPTER 4

LED MANUFACTURING

Light-emitting diodes (LEDs) — small colored lights available in any electronics store — are

ubiquitous in modern society. They are the indicator lights on our stereos, automobile dashboards,

and microwave ovens. Numeric displays on clock radios, digital watches, and calculators are

composed of bars of LEDs. LEDs also find applications in telecommunications for short range

optical signal transmission such as TV remote controls. They have even found their way into

jewelry and clothing — witness sun visors with a series of blinking colored lights adorning the brim.

The inventors of the LED had no idea of the revolutionary item they were creating. They were

trying to make lasers, but on the way they discovered a substitute for the light bulb.

Light bulbs are really just wires attached to a source of energy. They emit light because the wire

heats up and gives off some of its heat energy in the form of light. An LED, on the other hand,

emits light by electronic excitation rather than heat generation. Diodes are electrical valves that

allow electrical current to flow in only one direction, just as a one-way valve might in a water pipe.

When the valve is "on," electrons move from a region of high electronic density to a region of low

electronic density. This movement of electrons is accompanied by the emission of light. The more

electrons that get passed across the boundary between layers, known as a junction, the brighter the

light. This phenomenon, known as electroluminescence, was observed as early as 1907. Before

working LEDs could be made, however, cleaner and more efficient materials had to be developed.

LEDs were developed during the post-World War II era; during the war there was a potent interest

in materials for light and microwave detectors. A variety of semiconductor materials were

developed during this research effort, and their light interaction properties were investigated in

some detail. During the 1950s, it became clear that the same materials that were used to detect light

could also be used to generate light. Researchers at AT&T Bell Laboratories were the first to

exploit the light-generating properties of these new materials in the 1960s. The LED was a

forerunner, and a fortuitous byproduct, of the laser development effort. The tiny colored lights held

some interest for industry, because they had advantages over light bulbs of a similar size: LEDs

use less power, have longer lifetimes, produce little heat, and emit colored light.



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The first LEDs were not as reliable or as useful as those sold today. Frequently, they could only

operate at the temperature of liquid nitrogen (-104 degrees Fahrenheit or -77 degrees Celsius) or

below, and would burn out in only a few hours. They gobbled power because they were very

inefficient, and they produced very little light. All of these problems can be attributed to a lack of

reliable techniques for producing the appropriate materials in the 1950s and 1960s, and as a result

the devices made from them were poor. When materials were improved, other advances in the

technology followed: methods for connecting the devices electronically, enlarging the diodes,

making them brighter, and generating more colors.

The advantages of the LED over the light bulb for applications requiring a small light source

encouraged manufacturers like Texas Instruments

To make the semiconductor wafers, gallium, arsenic, and/or phosphor are first mixed together in a

chamber and forced into a solution. To keep them from escaping into the pressurized gas in the

chamber, they are often covered with a layer of liquid boron oxide. Next, a rod is dipped into the

solution and pulled out slowly. The solution cools and crystallizes on the end of the rod as it is

lifted out of the chamber, forming a long, cylindrical crystal ingot. The ingot is then sliced into

wafers.

To make the semiconductor wafers, gallium, arsenic, and/or phosphor are first mixed together in a

chamber and forced into a solution. To keep them from escaping into the pressurized gas in the

chamber, they are often covered with a layer of liquid boron oxide. Next, a rod is dipped into the

solution and pulled out slowly. The solution cools and crystallizes on the end of the rod as it is

lifted out of the chamber, forming a long, cylindrical crystal ingot. The ingot is then sliced into

wafers, and Hewlett Packard to pursue the commercial manufacture of LEDs. Sudden widespread

market acceptance in the 1970s was the result of the reduction in production costs and also of

clever marketing, which made products with LED displays (such as watches) seem "high tech"

and, therefore, desirable. Manufacturers were able to produce many LEDs in a row to create a

variety of displays for use on clocks, scientific instruments, and computer card readers. The

technology is still developing today as manufacturers seek ways to make the devices more

efficiently, less expensively, and in more colors.



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Fig 4.1 Making semiconductor wafers

4.1 RAW MATERIALS

Diodes, in general, are made of very thin layers of semiconductor material; one layer will have an

excess of electrons, while the next will have a deficit of electrons. This difference causes electrons

to move from one layer to another, thereby generating light. Manufacturers can now make these

layers as thin as .5 micron or less (1 micron = 1 ten-thousandth of an inch).

Fig 4.2 Adding Epitaxial Layers



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Impurities within the semiconductor are used to create the required electron density. A

semiconductor is a crystalline material that conducts electricity only when there is a high density

of impurities in it. The slice, or wafer, of semiconductor is a single uniform crystal, and the

impurities are introduced later during the manufacturing process. Think of the wafer as a cake that

is mixed and baked in a prescribed manner, and impurities as nuts suspended in the cake. The

particular semiconductors used for LED manufacture are gallium arsenide (GaAs), gallium

phosphide (GaP), or gallium arsenide phosphide (GaAsP). The different semiconductor materials

(called substrates) and different impurities result in different colors of light from the LED.

Impurities, the nuts in the cake, are introduced later in the manufacturing process; unlike

imperfections, they are introduced deliberately to make the LED function correctly. This process

is called doping. The impurities commonly added are zinc or nitrogen, but silicon, germanium, and

tellurium have also been used. As mentioned previously, they will cause the semiconductor to

conduct electricity and will make the LED function as an electronic device. It is through the

impurities that a layer with an excess or a deficit of electrons can be created.

To complete the device, it is necessary to bring electricity to it and from it. Thus, wires must be

attached onto the substrate. These wires must stick well to the semiconductor and be strong enough

to withstand subsequent

One way to add the necessary impurities to the semiconductor crystal is to grow additional layers

of crystal onto the wafer surface. In this process, known as "Liquid Phase Epitaxy," the wafer is

put on a graphite slide and passed underneath reservoirs of molten GaAsP.

Contact patterns are exposed on the wafer's surface using photoresist, after which the wafers are

put into a heated vacuum chamber. Here, molten metal is evaporated onto the contact pattern on

the wafer surface. Processing such as soldering and heating. Gold and silver compounds are most

commonly used for this purpose, because they form a chemical bond with the gallium at the surface

of the wafer.

LEDs are encased in transparent plastic, rather like the lucite paperweights that have objects

suspended in them. The plastic can be any of a number of varieties, and its exact optical properties

will determine what the output of the LED looks like. Some plastics are diffusive, which means

the light will scatter in many directions. Some are transparent, and can be shaped into lenses thatwill direct the light straight out from the LED in a narrow beam. The plastics can be tinted, which



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Fig 4.3 Mounting and Packaging of LED

A typical LED indicator light shows how small the actual LED is. Although the average

lifetime of a small light bulb is 5-10 years, a modern LED should last 100 years or more before

it fails

Optical requirements of the package (with a lens or connector at the end), and the mold is filled

with liquid plastic or epoxy. The epoxy is cured, and the package is complete.



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CHAPTER 5

ASSEMBLING OF LED LIGHTS

5.1 DRIVER ASSEMBLY

Fig 5.1 Driver Assembly

Driver assembly is the department where the LED’s are mounted on PCB’s using Surface MountTechnology. The complete work in done by machine.

5.1.1 SURFACE MOUNT TECHNOLOGY

Surface-mount technology (SMT) is a method for producing electronic circuits in which the

components are mounted or placed directly onto the surface of printed circuit boards (PCBs). The

Assembly line with SMT placement machine is shown in the fig 5.2 and 5.3 show the LED strips



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which are mounted on the PCBs. An electronic device so made is called a surface-mount device

(SMD). In the industry it has largely replaced the through-hole technology construction method of

fitting components with wire leads into holes in the circuit board.

Fig 5.2 Assembly line with SMT placement machine

Fig 5.3 LED Strips



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ADVANTAGES

The main advantages of SMT over the older through-hole technique are:

Smaller components. As of 2012 smallest was 0.4 × 0.2 mm (0.016 × 0.008 in: 01005).Expected to sample in 2013 are 0.25 × 0.125 mm (0.010 × 0.005 in, size not yet standardized)

Much higher component density (components per unit area) and many more connections per

component.

Lower initial cost and time of setting up for production.

Fewer holes need to be drilled.

Simpler and faster automated assembly. Some placement machines are capable of placing more

than 136,000 components per hour. Small errors in component placement are corrected automatically as the surface tension of

molten solder pulls components into alignment with solder pads.

Components can be placed on both sides of the circuit board.

Lower resistance and inductance at the connection; consequently, fewer unwanted RF signal

effects and better and more predictable high-frequency performance.

Better mechanical performance under shake and vibration conditions.

Many SMT parts cost less than equivalent through-hole parts.

Better EMC compatibility (lower radiated emissions) due to the smaller radiation loop area

(because of the smaller package) and the smaller lead inductance.

DISADVANTAGES

Manual prototype assembly or component-level repair is more difficult and requires skilled

operators and more expensive tools, due to the small sizes and lead spacings of many SMDs.

SMDs cannot be used directly with plug-in breadboards (a quick snap-and-play prototyping

tool), requiring either a custom PCB for every prototype or the mounting of the SMD upon a

pin-leaded carrier. For prototyping around a specific SMD component, a less-expensive

breakout board may be used. Additionally, stripboard style protoboards can be used, some of

which include pads for standard sized SMD components. For prototyping, "dead bug"

breadboarding can be used.

SMDs' solder connections may be damaged by potting compounds going through thermal

cycling.



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Solder joint dimensions in SMT quickly become much smaller as advances are made toward

ultra-fine pitch technology. The reliability of solder joints become more of a concern, as less

and less solder is allowed for each joint. Voiding is a fault commonly associated with solder

joints, especially when reflowing a solder paste in the SMT application. The presence of voids

can deteriorate the joint strength and eventually lead to joint failure.[5][6]

SMT is unsuitable for large, high-power, or high-voltage parts, for example in power circuitry.

It is common to combine SMT and through-hole construction, with transformers, heat-sinked

power semiconductors, physically large capacitors, fuses, connectors, and so on mounted on

one side of the PCB through holes.

SMT is unsuitable as the sole attachment method for components that are subject to frequent

mechanical stress, such as connectors that are used to interface with external devices that are

frequently attached and detached.



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CHAPTER 6

MANUAL ASSEMBLY OF LED LIGHTS

6.1 FRAME MOUNTING

Best way to accurately position strip, once you have decided where to mount it, is to draw or scratch

a guide line that you can follow with one edge of the LED strip, this will minimize handling and

over working the delicate flexible PC board.

Attach the LED Strip using the adhesive back to hold it in place before applying the 1” widefibreglass ribbon which runs along the length of the LED strip. Prepare surfaces with a solvent that

evaporates quickly but first, make sure it doesn't attack your existing finishes.

Leave the end contacts exposed for final connecting and sealing.

Masking off the area where the strip will adhere and then painting or spraying contact cement on

will give an exceptional bond when combined with the strip’s adhesive. Take care however,

because repositioning will be a problem once it grabs.

When applying the LED strip - first, peel the backing paper back about 2 inches and press the strip

into place, next, put a bit of tension on the LED strip holding it about a foot from the adhesion

point while applying it and peeling back the paper backing, 2-4 inches at a time, apply good

pressure with a finger every 1/2 inch or so. Make sure the adhesive has grabbed, this will assure

an even line of LEDs and provides the best heat transfer, which will help extend their performance.

Never just peel the LED strip off once it has bonded to a surface, instead use a thin scraper or dull

blade and slide it between the bonded surfaces while lifting the LED strip away and minimize

distorting it.

When applying the fibreglass, the best results can be had by brushing the resin onto the strip/pipe

area before applying the fibreglass then brushing another c oat over the ribbon once it’s been

applied. A small 1/2" disposable paint brush works well to dab out any air bubbles and ensure good

fibreglass contact over the LEDs.



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6.2 SOLDERING

Soldering is a process in which two or more metal items are joined together by melting and flowing

a filler metal (solder) into the joint, the filler metal having a lower melting point than the adjoiningmetal. Soldering differs from welding in that soldering does not involve melting the work pieces.

In brazing, the filler metal melts at a higher temperature, but the work piece metal does not melt.

In the past, nearly all solders contained lead, but environmental concerns have increasingly dictated

use of lead-free alloys for electronics and plumbing purposes.

LED strips have two common features which are important to this Instructable. First, LED strips

are divided into segments. The strips can be cut at any length provided the cut is on the line usuallyindicated by a small scissors icon. LED strips that are severed or cut between these lines will not

function to the fullest. Second, LED strips have a positive (+) and a negative (-) soldering hard

point that is on the strip. The convention does matter, since they run from DC power. There are a

pair of these points at the beginning and the end of each segment.

Step 1: Cut the LED strip along an indicated line to give you a length close to the desired length.

If you cut too long, you can always cut again, too short and you may have to do more soldering.

Step 2: Remove the waterproofing or plastic covering, if applicable, so that the soldering hard

points are free.

Step 3: Pre-tin the hard points. Pre-tinning refers to the procedure by which you solder a small

blob of solder onto the object in question. In order for this to work the best, you must heat up the

element so that the solder wicks onto it...not just lays on top and cools. This works best with a

conical soldering tip and a small amount of solder for thermal conductivity. Once the desired

temperature is reached, you will see the solder wick onto the surface. Add more in necessary. You

should have enough to cover the hard point, but not be at risk of melting through the strip or

reaching the other hard point, causing a short.



35

Fig 6.1 Soldering of LEDs

Step 4: Cut and strip the wire a desired length. Again, cut longer than you think you will need.

Strip only a small length of wire, like 1/8" or less. If the wire is stranded, twist the strands together

to keep them from separating. The best wire will be thin enough to move around tightly, I prefer

22-24 AWG solid core.

A quick word about current. LED strips sink current and depending on the length increase the

amperage of current in the circuit. Wires can extend the reach of your LED strips and do not count

towards the drawn current (measured in amperes, A or milliamperes, mA). Please refer to the

manufacturer's documentation for the specifics. Most segments take somewhere between 20 and

100 mA. For example, my five foot section from the hardware store totals 250mA...which is 1/4

of the total my DC adapter puts out, which is 1A or 1000mA.

Step 5: Pre-tin the end of the wire.



36

Step 6: Using helping hands or a vice, mount the wire and the strip so that it takes minimal or no

effort to get the wire and the hard point to touch.

Step 7: Quickly touch the soldering iron to the wire and the hard point at the same time. If we pre-

tinned our connections, they should quickly form a solid contact. Remove from heat.

6.3 LEAD CUTTINGS

Fig 6.2 LED Components Lead Cutting Machine



37

6.3.1 LED COMPONENTS LEAD CUTTING MACHINE

Size L1100 * W650 * H1050mm

Voltage 220V/50-60Hz

Feeding forms Feeding plane

Weight 145kg

Processing 150(pcs/min)

Efficiency 80-150pcs/min

Feet long 3-20 (mm)

Package Wooden case

Type Led Components Lead

Cutting Machine

Suit for bulk components cut work, suit for mass production, save manual labour

Special cutting method, blade imported from Japan, long service life and easy adjusted

High cutting accuracy, the shortest cutting length is 3 mm or 2.5 mm (Customer-made)

Feed table adopt imported fiber board

Feed table can be set according to the customer order, can install another counter according tothe customer requirements and the products

In order to guarantee the customers are able fully to operate the machine, if the customer need, we

can help customer training, includes:

Correct operating mode

Correct maintenance way



39

Instrument Systems has developed turnkey solutions for determining luminous intensity, luminous

flux, color, spectrum and spatial radiation pattern of LEDs. The measurement systems generate

very accurate results with reliable reproducibility.

Quality in semiconductor manufacturing takes two forms. The first concern is with the final

produced product, and the second with the manufacturing facility. Every LED is checked when it

is wire bonded for operation characteristics.

Specific levels of current should produce specific brightness.

Exact light color is tested for each batch of wafers, and

Some LEDs will be pulled for stress testing, including lifetime tests, heat and power

breakdown, and mechanical damage.



40

CHAPTER 7

CONCLUSION

Working with Autolite (India) Limited as a summer trainee was a very nice experience. I learnt a

lot about basics of LEDs and LED manufacturing. I also practiced what I learnt in the university

and applied it on field. Working with department enhanced my major understanding. In addition,

I gained a good experience in term of self-confidence, real life working situation, interactions

among people in the same field and working with others with different professional background. I

had an interest in understanding basic engineering work and practicing what has been learnt in the

class. Also, the training was an opportunity for me to increase my human relation both socially and

professionally.

I have learned about the working culture

During the training we gets to know about amount of hard work goes behind the making of a

products.

During the training one gets to know amount of hard work goes behind the making of a product

This experience gives us a direction and prepares us to get ready before a getting into a proper

job.



41

CHAPTER 8

LEARNINGS AND OUTCOMES

LED technology is used in Auto motive headlamps, signal lamps and for work lamps. The

production is done by Machines and Manual. Reflow oven and Reflow soldering are used for in

the manufacturing process of LEDs. During the training one gets to know amount of hard work

goes behind the making of a product. I got to learn about the working culture of the company and

how punctuality is important in making of a product.

I have learned about the different types of LED lights

According to their rating we learned about the applications of the lights

The manufacturing process of LED lights

I have learned about Surface Mount technology



REFERENCES

Books

[1.] Bergh, A. A. and P. J Dean. Light-Emitting Diodes. Clarendon Press

[2.] Gillessen, Klaus. Light-Emitting Diodes: An Introduction. Prentice Hall

[3.] Optoelectronics/Fiber-Optics Applications Manual. McGraw-Hill

[4.] Understanding Solid State Electronics. Radio Shack/Texas Instruments Learning Center

[5.] Williams, E. W. and R. Hall. Luminescence and the Light-Emitting Diode. Pergamon Press

Websites

[1.] http://www.circuitstoday.com/how-a-led-works-light-emitting-diode-working

[2.] http://electronics.howstuffworks.com/led4.htm

[3.] http://www.edisontechcenter.org/LED.html

[4.] http://www.madehow.com/Volume-1/Light-Emitting-Diode-LED.html

http://www.circuitstoday.com/how-a-led-works-light-emitting-diode-working



http://electronics.howstuffworks.com/led4.htm



http://www.edisontechcenter.org/LED.html



http://www.madehow.com/Volume-1/Light-Emitting-Diode-LED.html







autopal training report

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