MY REPORT (2)

1

SUBMITTED IN ACCOMPLISHMENT OF

(FROM 10th JUNE 2015 TO 9th JULY 2015)

SUBMITTED BY: SUBMITTED TO:

PAWAN KUMAR PANDEY Mr. RAJESH AGARWAL

B.TECH (ECE, 3rd YEAR) D.G.M (TRAINING)

G.N.I.O.T, GREATER NOIDA H.A.L. KORWA, AMETHI

ACKNOWLEDGEMENT

CERTIFICATE

CONCEPT OF TRAINING

IMPORTANCE OF TRAINING

HAL-AN ORGANISATION OVERVIEW

ABOUT FIGHTER PLANES

ABOUT HAL KORWA

INTRODUCTION

DEPARTMENTS

S.T.E.G.

FDR

INS

HUDWAC

PROJECT REPORT

PCB DESIGNING

SOLDERING

DO ’S & DONT ’S

This is to certify that the project report entitled “SPECIAL TEST EQUIPMENT

GROUP (STEG)” is a bonafide work of report developed by PAWAN KUMAR

PANDEY (Vocational Trainee, B.TECH. EC 3RD YEAR) period from 10TH

June,2015 to 09TH JULY ,2015. This training report forms a part of partial

fulfillment to B.Tech Degree course.

The produced report is genuine and has not been submitted elsewhere for any

reason whatsoever. I am fully satisfied and appreciate the work done on the

project. I wish good luck for the bright future of the candidate.

Sr.Manager (STEG)

HAL AVIONICS DIVN.

KORWA

It gives me immense pleasure to state that I have been given opportunity to

produce training report at HAL Avionics Division Korwa for a period of four

weeks. I have a long list of people to acknowledge and because of their active

efforts & suggestions the project has been completed well within the time schedule

& with the desired quality.

First of all I would like to acknowledge General Manager HAL Korwa for his kind

approval of my training. I would like to thank Mr. Rajesh Agarwal(DGM

Training),Mr. M.K NISHAD (Training Officer), and Mr. Gauri Shankar (Sr. CS,

Training) for my deputation in the prestigious S.T.E.G. Department. Also I would

like to thank Mr. Hemant Saxena (Sr. Manager), for devoting their prestigious

time.

My Special thanks and gratefulness to Mr. HEMANT SAXENA (Sr.

Manager,STEG), Mr. Mahesh Babu(Manager), Mr. R. C. Dwivedi (Dy.

Manager), Mr. A. S. Rathode, Mr. H. C. Pant, Mr. Ashok Kumar &

Pramendra Singh with whom I actually worked and learned the basics of work in

the industry as well as the practical knowledge.

PAWAN KUMAR PANDEY

CONCEPT OF TRAINING

Every organization needs to have

well trained and experienced

people to perform the activities

that have to be done. If the

current or potential job occupant

fail to meet this requirement,

training becomes important as it

raises the skill levels and increase

the versatility and adaptability of

the employees. Training becomes

all the important complex jobs.

In a rapidly changing society, employee, training is not only an activity that is

desirable but also an activity that an organization must committing source to, if it is

to maintain a viable and knowledgeable work force.

Training is a process of learning a sequence of behavior; it is an application of

knowledge. It gives people an awareness of the rules and procedure to guide their

behavior. It attempts to improve their performance on the current job or prepare

them for an intended job.

IMPORTANCE OF TRAINING

Training is the corner stone of sound management, for it makes employees more

effective and productive. It is actively and intimately connected with all the

personnel and managerial activities. It is

an integral part of the whole

management programmer with all its

activities functionally inter related.

Training is a practical and vital necessity because, a part from the other advantages

mentioned earlier, it enables employees to develop and rise within the organization

and increases their market value, earning power and job security. It enables

management to resolve sources of friction and make then aware of the fact that the

management is not divisible, it helps them to achieve better co-operation with the

company and a greater loyalty to it. Training, on the hand, benefits the

management by high standards of quality and on the other hand heightens to

morale of the employees because it helps in reducing dissatisfaction, complaints,

grievances, and absenteeism and also reduces the rate of turnover.

Hindustan Aeronautics Limited (HAL) came into existence on 1st October

1964. The Company was formed by the merger of Hindustan Aircraft Limited with

Aeronautics India Limited and Aircraft Manufacturing Depot, Kanpur.

The Company traces its roots to the pioneering efforts of an industrialist with

extraordinary vision, the late Seth Walchand Hirachand, who set up Hindustan Aircraft

Limited at Bangalore in association with the erstwhile princely State of Mysore in

December 1940. The Government of India became a shareholder in March 1941 and

took over the Management in 1942.

Today, HAL has 19 Production Units and 9 Research and Design Centres in 7

locations in India. The Company has an impressive product track record - 12 types of

aircraft manufactured with in-house R & D and 14 types produced under license. HAL

has manufactured over 3550 aircraft , 3600 engines and overhauled

over 8150 aircraft and 27300 engines.

HAL has been successful in numerous R & D programs developed for both Defence

and Civil Aviation sectors. HAL has made substantial progress in its current projects :

Dhruv, which is Advanced Light Helicopter (ALH)

Tejas - Light Combat Aircraft (LCA)

Intermediate Jet Trainer (IJT)

Various military and civil upgrades.

Dhruv was delivered to the Indian Army, Navy, Air Force and the Coast Guard in

March 2002, in the very first year of its production, a unique achievement.

HAL has played a significant role for India's space programs by participating in the

manufacture of structures for Satellite Launch Vehicles like

PSLV (Polar Satellite Launch Vehicle)

GSLV (Geo-synchronous Satellite Launch Vehicle)

IRS (Indian Remote Satellite)

INSAT (Indian National Satellite)

HAL has formed the following Joint Ventures (JVs) :

BAeHAL Software Limited

Indo-Russian Aviation Limited (IRAL)

Snecma HAL Aerospace Pvt Ltd

SAMTEL HAL Display System Limited

HALBIT Avionics Pvt Ltd

HAL-Edgewood Technologies Pvt Ltd

INFOTECH HAL Ltd

Apart from these seven, other major diversification projects are Industrial Marine Gas

Turbine and Airport Services. Several Co-production and Joint Ventures with

international participation are under consideration.

HAL's supplies / services are mainly to Indian Defence Services, Coast Guards and

Border Security Forces. Transport Aircraft and Helicopters have also been supplied to

Airlines as well as State Governments of India. The Company has also achieved a

foothold in export in more than 30 countries, having demonstrated its quality and price

competitiveness.

HAL has won several International & National Awards for achievements in R&D,

Technology, Managerial Performance, Exports, Energy Conservation, Quality and

Fulfillment of Social Responsibilities.

HAL was awarded the “INTERNATIONAL GOLD MEDAL AWARD” for

Corporate Achievement in Quality and Efficiency at the International Summit

(Global Rating Leaders 2003), London, UK by M/s Global Rating, UK in

conjunction with the International Information and Marketing Centre (IIMC).

HAL was presented the International - “ARCH OF EUROPE” Award in Gold

Category in recognition for its commitment to Quality, Leadership, Technology

and Innovation.

At the National level, HAL won the "GOLD TROPHY" for excellence in Public

Sector Management, instituted by the Standing Conference of Public Enterprises

(SCOPE).

DIVISIONS OF HAL

ABOUT FIGHTER PLANES:

The SEPECAT Jaguar is an Anglo-French jet

ground attack aircraft still in service with

several export customers, notably the Indian

Air Force and the Royal Air Force of Oman.

It was among the first major Anglo-French

military aircraft programs. The aircraft served

as one of the French Air Force's main

strike/attack aircraft until 1 July 2005 (when it was replaced by Dassault Rafale) and with

the Royal Air Force until the end of April 2007.

HAL commenced production of Jaguar International - deep penetration strike and

battlefield tactical Support Aircraft in 1979 under licence from British Aerospace,

including the engine, accessories and avionics.

Jaguar aircraft is designed with 7 hard points (4 under wing, 2 over wing and 1 under

fuselage) capable of carrying a huge load of several of weapons in different combinations

to meet the Customers needs.

Basic Data

Dimensions Wing Data Weight Fuel

Capacity

Power Plant

Length:

16.955 m

Wing Span:

8.691 m

Height:

4.813 m

Area:

24.03 m2

Sweep:

40o 2'

Aspect Ratio:

3.12

Maximum

Take Off:

15700 kg

Pay Load:

4000 kg

Internal :

4.171 liters

With ext.

tanks (max

usable

capacity):

7726 liters

Rolls Royce

Adour MK 811

Turbofan

Max. thrust at sea

level:

Dry - 2549 kg

Reheat - 3810 kg

The Sukhoi Su-30 MKI (NATO reporting name: Flanker-H) is a variant of the Sukhoi

Su-30 jointly-developed by Russia's Sukhoi Corporation and India's Hindustan Aeronautics

Limited (HAL) for the Indian Air

Force (IAF). It is a heavy class, long-

range air superiority fighter which ca n

also act as a multirole, strike

fighter aircraft.

The development of the variant started

after India signed a deal with Russia in

2000 to manufacture 140 Su-30 fighter

jets. The first Russian-made Su-

30MKI variant was integrated into the

IAF in 2002, while the first indigenous Su-

30MKI (with Russian engine) entered

service with the IAF in 2004. In 2007, the IAF ordered 40 additional MKIs. As of October

2009, the IAF had 105 MKIs under active service with plans to have an operational fleet of

280 MKIs by 2015. The Su-30MKI is expected to form the backbone of the Indian Air

Force's fighter fleet to 2020 and beyond.

The aircraft is tailor-made for Indian specifications and integrates Indian systems and

avionics as well asFrench and Israeli subsystems. It has abilities similar to the Sukhoi Su-

35 with which it shares many features and components

The Dassault Mirage 2000 is a French multirole, single-engine fourth-generation jet fighter

manufactured by Dassault Aviation. It was designed as a lightweight fighter based on the Mirage

III in the late 1970s for the French Air Force.The Mirage 2000 evolved into a successful multirole

aircraft with several variants developed.

The variants include the Mirage 2000N and

2000D strike variants, the improved Mirage 2000-

5 and several export variants. Over 600 aircraft

were built and it is in service in nine countries as

of 2009.

The Mirage 2000 features a low-set thin

delta wing with cambered section, 58

degrees leading-edge sweep (4 at the exit

wing border) and moderately

blended root; area-ruled; two small canard wings, fixed, placed just behind the air intakes.

The flight commands on the wing are: four elevons (+15/-30°), four slats, four airbrakes (2

above and 2 below each wing).

Its neutral point is in front of its center of gravity, giving the fighter relaxed stability to

enhance maneuverability. It was the first fighter jet to incorporate negative stability and

fly-by-wire controls in its design. An airbrake is fitted on top and below each wing in an

arrangement very similar to that of the Mirage III. A noticeably taller tailfin allows the

pilot to retain control at higher angles of attack, assisted by small strakes mounted along

each air intake.

It has a runway arresting hook or fairing for a brake parachute can be fitted under the tail.

The landing roll was reduced by robust carbon brakes. The backward-retracting, steerable

nose gear features dual wheels, while the main gear features single wheels and retracts

inward into the wings. A parachute brake is on the tail, just above the engine exhaust.

A fixed removable refueling probe can be attached in front of the cockpit, offset slightly to

the right of center.

AVIONICS DIVISION, KORWA IS INVOLVED IN THE MANUFACTURE OF

ADVANCED AVIONICS

SYSTEMS LIKE INERTIAL

NAVIGATION

SYSTEM(INS),COMBINED MAP

AND ELECTRONIC

DISPLAY(COMED),HEAD UP

DISPLAY & WEAPON AIMING

COMPUTER(HUDWAC),LASER

RANGER AND MARKED

TARGET

SEEKER(LRMTS),AUTOSTABILI

ZER AND FLIGHT DATA

RECORDER(FDR).

THE DIVISION HAS ALSO ESTABLISHED THE FACILITIES FOR DEPOT

LEVEL MAINTENANCE FACILITIES FOR DIGITAL MAP GENERATOR

(DMG), HEAD UP DISPLAY (HUD) FOR JAGUAR AND SU-30 AIRCRAFT

AND PRODUCTION FACILITIES FOR MANUFACTURE OF MULTI

FUNCTION DISPLAY(MFD) FOR SU-30 MKI AIRCRAFT.

Products in Current Manufacturing Range

Currently the Korwa Division manufactures the Navigation, Ranging, Display and

Attack Systems for both Jaguar and MiG-27M aircraft.

Brief details of the avionic system are as under:

JAGUAR AVIONICS

Inertial Navigation System

o Stabilized Inertial Platform with Dry-tuned Gyroscopes and

Accelerometers

o Digital Nav-Attack Computer

o Interface Unit and Cockpit Control Panels

Head-Up Display & Weapon Aiming Computer (HUDWAC)

o Microprocessor based head-up

Display & Sighting System

o Scan and Cursive modes of display

o Weapon Aiming Computations in

Reversionary modes in the event of

failure of INS Computer

o Head Down Navigation & Map

Display

o Soft key Selectable Display

Modes

o Integrated with INS and HUDWAC on MIL-STD 1553B Digital Data

Bus

Flight Data Recorder (FDR)

o Crash protected Flight Data Recording System with Data Acquisition

Unit

o Simultaneous recording of Data and Audio tracks

o Recording duration of 90 minutes in endless loop

Laser Ranger and Marked Target Seeker (LRMTS)

o Operates both in Ranging and Target Seeking modes

o Target Range Computation

o Neodymium Doped YAG Laser

Autostabliser System (AUTOSTAB)

o Computer Based System for Control of Tailplane, Rudder and Spoiler

Movements

o Incorporate BITE Facility

MiG-27M AVIONICS

Integrated Navigation and Sighting Complex

(44 LK System)

Inertial Navigation System

Centralized Digital Computer

Radio and Doppler Navigation

Stabilised Sight

Air Data Computer

Laser Ranging System

Flight Data Recorder (UZL TESTER)

Recording Duration of 3 Hours

Crash Protected Recording System

Records 38 Analogue and 32 Discrete Parameters

DEPARTMENTS

Departments under HAL Korwa are categorized for the proper functioning of the

division. These departments have their functional heads supported by other

executives and workers. The functional heads report directly to General Manager

who in turn reports to respective MD.

These departments are as follows:

Assembly and Testing (MIG)

Manufacturing

Assembly and Testing (Jaguar)

Tool Design

STEG

Management Services Department

Design

Vigilance

Commercial and Purchase

Civil;

Process Shop;

Finance/ Account;

Training Department;

Plant Maintenance;

Quality Control;

Admin and Personnel;

Computer Section;

Security;

Su-30

SPECIAL TEST EQUIPMENT

GROUP (S.T.E.G.)

Testing of Equipment’s

1. Transistor

2. Resistance

3. Diode

4. Capacitor

The special to type test equipment group (STEG) at HAL Korwa has been involved

in Design, fabrication and maintenances of various kinds of special to type test

equipment. This play a vital role in the house development of different test

equipment, test rigs, jigs and fixtures, high vacuum systems and optical test

benches for testing of precision gyros, accelerometers and associated electronics.

Equipment designed developed at STEG are in regular use at various avionics

labs, testing of LRU in assembly shops of our division, air fours bases throughout

the country and other division .Accordingly this department has been nominated as

a nodal agency for making of test equipment for other divisions. This group also

provides maintenance support of standard test equipment and test equipment

manufactured by the department to the division.

This department is the backbone of H.A.L. as it the main group of Quality Control.

This is the main group which involves testing of electronic equipments and

instruments used in the factory. All the equipments of the factory are tested and

calibrated against the working standard. These standards are compatible to the

N.P.L. Standards. All those equipments, which fail in the tests, are repaired.

So at the functional point of view, this department is divided into two main groups.

1. Calibration Lab.

2. Repair Shop

S.T.E.G. is also involved in the production of new

instruments used in Avionics.

1. CALIBRATION LAB: This is the lab where the different instruments and

equipment are calibrated against the working standards and ideal standards

under the ideal physical conditions from all the different departments of the

H.A.L. the electronics instruments are rushed here for calibration.

2. REPAIR SHOP: This lab is mainly concerned with repair of damaged

electronic equipments from any part of the factory. The basic strategy

followed is cold testing of each component such as diode, transistor, relays,

IC’s. Once found faulty, they are replaced and again the output is checked.

SPECIAL TEST EQUIPMENT GROUP (S.T.E.G.)

The special to type test equipment group (STEG) at HAL Korwa is involved in

fabrication and maintenance of various kinds of “special to type test

equipment”.

The Objective of STEG Department is as follows :

Design, Modification and manufacture of Special Type Test Equipment

(STTE)

Repair and servicing of commercial, Standard Test Equipment &

indigenously manufactured test equipment for various shops over the

years.

The main activities of STEG (Special Test Equipment Group) includes:

1. Scrutinize the work order for the production of test equipments.

2. Fabrication, Production and maintenance of test equipments.

3. To develop in house test equipments like Test Rigs, Optical test benches,

High Vacuum systems, for testing of precision instrument such as Gyros,

Accelerometer and associated electronics etc.

4. To provide maintenance support of standard test equipments.

5. Procurement action for spare parts.

6. Outsourcing of repair of Special Test Equipments.

Various types of Special type Test Equipments STEG are produced in STEG

catering to different requirements:

O-LEVEL (Operational level)

These benches are meant for 1st level maintenance of units at Air

bases and are of GO/NOGO type which gives the output whether unit

under test is PASS/FAIL.

I-LEVEL(Intermediate level)

It is meant for fault diagnosis/functionality testing up-to Module

level at (Assembled PCB) level.

D-LEVEL ( Depot level)

It is meant for fault diagnosis/functionality testing up-to component

level and it is primarily used for component level repair of the

PCBs/Module. This type of Test equipments are essential for repair

agencies/OEM for detail investigation & repair.

PROJECT:

To study various electronic measuring equipments used in STEG

Following equipments has been studied:

1. DRU(Data Retrieval Unit)

2. Digital Multi-meter

3. Cathode Ray Oscilloscope

4. Function Generators

5. Power supplies

Data Retrieval Unit

This test bench is presently under development/manufacturing by STEG. It

is used for testing of various parameters of SSFDR like power supply,

frequency parameter, analog parameter, data recording and retrieval etc.

The bench is fully designed & developed in-house at KORWA. All

mechanical parts (chassis) are fabricated in-house tool room. PCB

assembly/wiring/interconnections are done at STEG.

Ground Replay Equipment (GRE) :

The real-time data of various aircraft parameters recorded in the Flight Data

Recorder (FDR) are downloaded and replayed on the ground with the help of the

GRE. The application software will run on the Host PC (GRE) and will acquire the

recorded data from the FDR through Asynchronous serial communication link

(RS422). A suitable adapter card with suitable device driver software is used to

access this asynchronous serial communication channel (RS422) through the USB

port.

The time tag information recorded on FDR is used as an absolute reference. The

recorded data acquired from the FDR is stored in the hard disk in prescribed format

for further analysis and retrieval.

The proposed system consists of the following.

1. A Laptop system.

2. A USB RS422 adaptor.

3. Printer.

4. Power Supply Unit.

5. Battery Backup.

6.

RS 422

CONVERTER

FLIGHT

DATA

RECORDER

POWER SUPPLY

PRINTER

LAPTOP

EXTERNAL INTERFACE

3. REPAIR GROUP:

This lab is mainly concerned with repair of damaged electronic equipments

from any part of the factory. The basic strategy followed is cold testing of each

component such as diode, transistor, relays, IC’s. Once found faulty, they are

replaced and again the output is checked.

A flight data recorder (FDR) (also ADR, for accident data recorder) is a kind of

flight recorder. It is a device used to record specific aircraft performance

parameters. Another kind of flight recorder is the cockpit voice recorder (CVR),

which records conversation in the cockpit, radio communications between the

cockpit crew and others (including

conversation with air traffic control

personnel), as well as ambient

sounds. In some cases, both functions

have been combined into a single

unit. The current applicable FAA

TSO is C124b titled Flight Data

Recorder Systems.

Popularly referred to as a "black

box," the data recorded by the FDR is used for accident investigation, as well as for

analyzing air safety issues, material degradation and engine performance. Due to

their importance in investigating accidents, these ICAO-regulated devices are

carefully engineered and stoutly constructed to withstand the force of a high speed

impact and the heat of an intense fire. Contrary to the "black box" reference, the

exterior of the FDR is coated with heat-resistant bright Red paint for high visibility

in wreckage, and the unit is usually mounted in the aircraft's empennage (tail

section), where it is more likely to survive a severe crash.

DESIGN

The design of today's FDR is governed by the internationally recognized standards

and recommended practices relating to flight recorders which are contained in

ICAO Annex 6 which makes reference to industry crashworthiness and fire

protection specifications such as those to be found in the European Organisation

for Civil Aviation Equipment documents EUROCAE ED55, ED56 fiken A and

ED112 (Minimum Operational Performance Specification for Crash Protected

Airborne Recorder Systems). In the United States, the Federal Aviation

Administration (FAA) regulates all aspects of U.S. aviation, and cites design

requirements in their Technical

Standard Order, based on the

EUROCAE documents (as do the

aviation authorities of many other

countries).

Currently, EUROCAE specifies that a

recorder must be able to withstand an

acceleration of 3400 g (33 km/s²) for

6.5 milliseconds. This is roughly equivalent to an impact velocity of 270 knots

(310 mph) and a deceleration or crushing distance of 450 cm. Additionally, there

are requirements for penetration resistance, static crush, high and low temperature

fires, deep sea pressure, sea water immersion, and fluid immersion

GROUND REPLAY EQUIPMENT:

The real-time data of various aircraft parameters recorded in the Flight Data

Recorder (FDR) are downloaded and replayed on the ground with the help of the

GRE.the application software will run on the host PC (GRE)and will acquire the

recorded that from the FDR through asynchronous serial communication link

(RS422). A suitable adapter card with suitable device driver software is used to

access this asynchronous serial communication channel (RS422) through the usb

port.

The time tag information recorded on FDR is used as an absolute reference.the

recorded data is acquired from the FDR is stored in the hard disk in prescribed

format for futher analysis and retrieval.

the proposed system consists of the following:

A laptop system

A USB RS422 adaptor

Printer

Power supply unit

Battery back up.

PRINTER

LAPTOP

RS 422

CONVERTER

BATTERY BACKUP

FLIGHT DATA

RECORDER

POWER SUPPLY

PROJECT:

To study various electronic meteorological measurement equipments.

INTRODUCTION:

Today in the present era, in every industry there is need of electronic

gadgets. Without these equipment’s the work would really be impossible. For

better accuracy sophisticated equipment’s are used. So my area of project covers

all the most sophisticated electronic equipment’s that are used in every generators,

Digital millimeters, Counters and Power supplies.

SCOPE:

These equipments are studied and limited to following scope:

o Operation and function.

o Specification and accuracies.

o Block diagram and working principles.

o Calibration needs.

The following equipments are studied in this project are:

Various types of Digital Multimeter

(HP34401).

Various types of CRO’s (TEKTRONICS).

Function Generators (HELWETT

PACKERD).

Various power supplies (HIL, APLAB).

CAPACITOR CODING

Capacitor Number Code

A number code is often used on small capacitors where printing is difficult:

the 1st number is the 1st digit,

the 2nd number is the 2nd digit,

the 3rd number is the number of

zeros to give the capacitance in pF.

Ignore any letters - they just

indicate tolerance and voltage

rating.

Capacitor Colour Code

A colour code was used on polyester

capacitors for many years. It is now

obsolete, but of course there are many

still around. The colours should be read like the resistor code, the top three colour

bands giving the value in pF. Ignore the 4th band (tolerance) and 5th band (voltage

rating).

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 (PWB) or etched wiring board. A PCB

populated with electronic components is a printed circuit assembly (PCA), also

known as a printed circuit board assembly (PCBA).

PCBs are inexpensive, and can be highly reliable. They require much more layout

effort and higher initial cost than either wire-wrapped or point-to-point constructed

circuits, but are much cheaper and faster for high-volume production.

Manufacturing

Materials:

Conducting layers are typically made of thin copper foil. Insulating layers

dielectric are typically laminated together with epoxy resin prepreg. The board is

typically coated with a solder mask that is green in color. Other colors that are

normally available are blue and red. There are quite a few different dielectrics that

can be chosen to provide different insulating values depending on the requirements

of the circuit. Some of these dielectrics are polytetrafluoroethylene (Teflon), FR-4,

FR-1, CEM-1 or CEM-3.

Patterning (etching):

The vast majority of printed circuit boards are made by bonding a layer of copper

over the entire substrate, sometimes on both sides, (creating a "blank PCB") then

removing unwanted copper after applying a temporary mask (e.g. by etching),

leaving only the desired copper traces. A few PCBs are made by adding traces to

the bare substrate (or a substrate with a very thin layer of copper) usually by a

complex process of multiple electroplating steps.

There are three common "subtractive" methods (methods that remove copper) used

for the production of printed circuit boards:

1. Silk screen printing uses etch-resistant inks to protect the copper foil.

Subsequent etching removes the unwanted copper. Alternatively, the ink

may be conductive, printed on a blank (non-conductive) board. The latter

technique is also used in the manufacture of hybrid circuits.

2. Photoengraving uses a photo mask and chemical etching to remove the

copper foil from the substrate. The photo mask is usually prepared with a

photo plotter from data produced by a technician using CAM, or computer-

aided manufacturing software. Laser-printed transparencies are typically

employed for photo tools; however, direct laser imaging techniques are

being employed to replace photo tools for high-resolution requirements.

3. PCB milling uses a two or three-axis mechanical milling system to mill

away the copper foil from the substrate. A PCB milling machine (referred to

as a 'PCB Prototyper') operates in a similar way to a plotter, receiving

commands from the host software that control the position of the milling

head in the x, y, and (if relevant) z axis. Data to drive the Prototyper is

extracted from files generated in PCB design software and stored in HPGL

or Gerber file format

4. Lamination

5. Some PCBs have trace layers inside the PCB and are called multi-layer

PCBs. These are formed by bonding together separately etched thin boards.

Drilling:

Holes through a PCB are typically drilled with tiny drill bits made of solid tungsten

carbide. The drilling is performed by automated drilling machines with placement

controlled by a drill tape or drill file. These computer-generated files are also

called numerically controlled drill (NCD) files or "Excellon files". The drill file

describes the location and size of each drilled hole. These holes are often filled

with annular rings (hollow rivets) to create vias. Vias allow the electrical and

thermal connection of conductors on opposite sides of the PCB.

Exposed conductor plating and coating:

PCBs are plated with solder, tin, or gold over nickel as a resist for etching away the

unneeded underlying copper. Matte solder is usually fused to provide a better

bonding surface or stripped to bare copper. Treatments, such as

benzimidazolethiol, prevent surface oxidation of bare copper. The places to which

components will be mounted are typically plated, because untreated bare copper

oxidizes quickly, and therefore is not readily solderable. Traditionally, any exposed

copper was coated with solder by hot air solder leveling (HASL). This solder was a

tin-lead alloy, however new solder compounds are now used to achieve

compliance with the RoHS directive in the EU and US, which restricts the use of

lead. One of these lead-free compounds is SN100CL, made up of 99.3% tin, 0.7%

copper, 0.05% nickel, and a nominal of 60ppm germanium.

Solder resist:

Areas that should not be soldered may be covered with a polymer solder resist

(solder mask) coating. The solder resist prevents solder from bridging between

conductors and creating short circuits. Solder resist also provides some protection

from the environment. Solder resist is typically 20-30 microns thick.

Screen printing:

Line art and text may be printed onto the outer surfaces of a PCB by screen

printing. When space permits, the screen print text can indicate component

designators, switch setting requirements, test points, and other features helpful in

assembling, testing, and servicing the circuit board.

Screen print is also known as the silk screen, or, in one sided PCBs, the red print.

Printed circuit assembly:

After the printed circuit board (PCB) is completed, electronic components must be

attached to form a functional printed circuit assembly, or PCA (sometimes called a

"printed circuit board assembly" PCBA). In through-hole construction, component

leads are inserted in holes. In surface-mount construction, the components are

placed on pads or lands on the outer surfaces of the PCB. In both kinds of

construction, component leads are electrically and mechanically fixed to the board

with a molten metal solder.

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 relatively

low melting point. Soft soldering is

characterized by the melting point of the

filler metal, which is below 400 °C

(752 °F).[1] The filler metal used in the

access is called solder.

APPLICATIONS

One of the most frequent applications of soldering is assembling electronic

components to printed circuit boards (PCBs). Another common application is

making permanent but reversible connections between copper pipes in plumbing

systems. Joints in sheet metal objects such as food cans, roof flashing, rain gutters

and automobile radiators have also historically been soldered, and occasionally still

are. Jewelry components are assembled and repaired by soldering. Small

mechanical parts are often soldered as well. Soldering is also used to join lead

came and copper foil in stained glass work. Soldering can also be used as a semi-

permanent patch for a leak in a container or cooking vessel.

SOLDER

Common solder alloys are mixtures of tin and lead, respectively:

63/37: melts at 183 °C (361 °F) (eutectic: the only mixture that melts at a

point, instead of over a range)

60/40: melts between 183–190 °C (361–374 °F)

50/50: melts between 185–215 °C (365–419 °F)

FLUX

In high-temperature metal joining processes (welding, brazing and soldering), the

primary purpose of flux is to prevent oxidation of the base and filler materials. Tin-

lead solder, for example, attaches very well to copper, but poorly to the various

oxides of copper, which form quickly at soldering temperatures. Flux is a

substance which is nearly inert at room temperature, but which becomes strongly

reducing at elevated temperatures, preventing the formation of metal oxides.

Secondarily, flux acts as a wetting agent in the soldering process, reducing the

surface tension of the molten solder and causing it to better wet out the parts to be

joined.

BASIC SOLDERING TECHNIQUES:

Soldering operations can be performed with hand tools, one joint at a time, or en

masse on a production line. Hand soldering is typically performed with a soldering

iron, soldering gun, or a torch, or occasionally a hot-air pencil. Sheetmetal work

was traditionally done with "soldering coppers" directly heated by a flame, with

sufficient stored heat in the mass of the soldering copper to complete a joint;

torches or electrically-heated soldering irons are more convenient. All soldered

joints require the same elements of cleaning of the metal parts to be joined, fitting

up the joint, heating the parts, applying flux, applying the filler, removing heat and

holding the assembly still until the filler metal has completely solidified.

Depending on the nature of flux material used, cleaning of the joints may be

required after they have cooled.

PIPE SOLDERING:

Copper pipe, or 'tube', is commonly joined by soldering. Copper is an outstanding

conductor of heat, therefore it requires more heat than a soldering iron or gun can

provide, so a propane torch is most commonly used; for large jobs a MAPP or

acetylene torch is used.

Solder fittings, which are short sections of smooth pipe designed to slide over the

outside of the mating tube, are usually used for copper joints. There are two types

of fittings: end feed fittings which contain no solder, and solder ring fittings, in

which there is a ring of solder in a small circular recess inside the fitting.

DESOLDERING:

Used solder contains some of the dissolved base metals and is unsuitable for reuse

in making new joints. Once the solder's capacity for the base metal has been

achieved it will no longer properly bond with the base metal, usually resulting in a

brittle cold solder joint with a crystalline appearance.

It is good practice to remove solder from a joint prior to resoldering—desoldering

braids or vacuum desoldering equipment (solder suckers) can be used. Desoldering

wicks contain plenty of flux that will lift the contamination from the copper trace

and any device leads that are present. This will leave a bright, shiny, clean junction

to be resoldered.

The lower melting point of solder means it can be melted away from the base

metal, leaving it mostly intact, though the outer layer will be "tinned" with solder.

Flux will remain which can easily be removed by abrasive or chemical processes.

This tinned layer will allow solder to flow into a new joint, resulting in a new joint,

as well as making the new solder flow very quickly and easily.

SOLDERING DEFECTS:

Some of the common soldering defects are:

Cold Joint

Fractured Joint

Improperly bonded joints

Excessive / Less solder

Rosin Joint

Wetting / Non wetting

Pin holes / Blowholes

DO׳S

1. TO be ensure that the input voltage of 230vac, ±10v of 50Hz is present in

clean room.

2. Take to care avoid short circuit & with measuring clip & hooks if the

instruments is switched ON, near input terminal when high voltage are

present.

3. Fault finding activities are started read the instruction about Before

switching ON the test equipment whenever operation /servicing /

maintenance procedure.

4. Maintain the norms of IS/ISO 1400-2004(environmental control)

5. During soldering & dislodging period keep temp. of soldering /disordering

station to the optimum value i.e. 300degreeC ±5dehreeC approx. always use

lead free solder.

6. Use only original /equipment spare parts. The spare should be checked

before replacement of them during repairing of equipments.

7. Ensure that all working station should be prepared with all types of

measuring equipments with testing accessories in calibrated condition.

8. Before attempting to repair of equipment it is necessary to read the nature of

fault given by user in repair.

9. After production /repairing /maintenance of the test equipment must be

calibrated in calibration lab. After calibration of equipments will be send to

user (shop) agency.

10. Routine calibration of test equipments to be updated.

DONT’S

1. Don’t start the equipment ´ON in uncontrolled atmospheric condition of

clean room.

2. No equipment will be switched ´ON´/start in beyond suggested

tolerance/limit of input supply voltage.

3. During testing of the high voltage 500V-25000V at least two operators

should available to the workstation.

4. Don’t start faultfinding /repair maintenance of test equipment without

reading the operation /servicing/maintenance manual.

5. No wastages like cleaning reagents , expired consumable & plastic should

not be scattered on roof because it disturb to the norms of ISO 1401-2004.

6. During soldering /disordering period don’t keep the temp. of the soldering

station beyond given range , item cane damage /burst/burnt or loose their

original value.

7. Don’t use spare parts on random selection basis as may it cause failure of

test equipments.

8. Don’t use wrong /faulty measuring equipment with improper accessories

during production /repair of equipments.

9. Nature of fault must be diagnosed at first ,because most of the time

consumed by operator, Secondly it is also very harmful for operator’s daily

man hours calculation.

10. Don’t send the production /repairing /maintenance of test equipment/items

to user without calibration. because the non-calibrated equipment gives

wrong results , which is dangerous for testing of modules/unit.

11. Without routine calibration of equipments wrong readings are obtained

which may results failure of the modules as per testing procedures.