GUJARAT TECHNOLOGICAL UNIVERSITY

(Established under Gujarat Act No. 20 of 2007)

ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

A Summer Internship Report on

“PRINTED CIRCUIT BOARD MANUFACTURING”
At the company
GENUS ELECTROTECH LIMITED
Under the subject
Summer Internship (3170001)

Submitted by
PRAJAPATI DHAVAL KISHORBHAI
210150119018
In partial fulfillment for the award of the degree of
BACHELOR OF ENGINEERING
in
Mechanical Engineering Department
Government Engineering College, Bhuj

Gujarat Technological University, Ahemdabad

JUNE 2024
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

GOVERNMENT ENGINEERING COLLEGE, BHUJ

Near Uma Nagar, New Ravalwadi Relocation Site, Mirzapar Road, Bhuj

CERTIFICATE
This is to certify that the project report submitted along with the project entitled
Internship has been carried out by Prajapati Dhaval Kishorbhai under my
guidance in partial fulfillment for the degree of Bachelor of Engineering in
Mechanical Engineering, 7th Semester of Gujarat Technological University,
Ahmadabad during the academic year 2024-25.

Prof. Y N Mansuri Prof. P R Rathod

Internal Guide Head of the Department

 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

Summer Internship Approval Certificate

(3170001)

This is to certify that the Summer Internship Report entitled Printed Circuit Board
Manufacturing submitted by Prajapati Dhaval Kishorbhai (210150119018) of Mechanical
Engineering during the academic year 2024-25 (B.E. – 4th Year, 7th Semester), of the
Government Engineering College-Bhuj has been found satisfactory and hence hereby
approved.

Date:

Place: Government Engineering College-Bhuj

Examiners:

Name Sign

1.

2.
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

GOVERNMENT ENGINEERING COLLEGE, BHUJ

Near Uma Nagar, New Ravalwadi Relocation Site, Mirzapar Road, Bhuj

DECLARATION

We hereby declare that the Internship report submitted along with the Internship
entitle “Printed Circuit Board Manufacturing” submitted in partial fulfillment
for the degree of Bachelor of Engineering in Mechanical to Gujarat Technological
University, Ahmedabad, is a bonafide record of original project work carried out
by me at GEC Bhuj under the supervision of Prof. Yasmin Mansuri and that no
part of this report has been directly copied from any students’ reports or taken
from any other source, without providing due reference.

Name of the student Sign of the student

1. Prajapati Dhaval k.

ⅰ
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

ACKNOWLEDGEMENT

First I would like to thank Ms. Payal, HR, of GENUS ELECTROTECH LTD, for giving me
the opportunity to do an internship within the organization.

I sincerely thank Mr. Vivek Tripathi, Mr. Saurav & Mr. Sandeep Prajapati for their guidance
and encouragement in carrying out this training work. I Also wish to express my gratitude to
the officials and other staff members of GENUS ELECTROTECH LTD. Who rendered their
help during the period of my training work.

I also thank the Production Manager of PCB plant of GENUS ELECTROTECH LTD. Mr.
V.Manoharan for providing me the opportunity to embark on this training work.

Prajapati Dhaval k.

(210150119018)

ⅱ
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

Abstract

This internship report provides a comprehensive overview of the Printed Circuit Board
(PCB) manufacturing process, focusing on the practical experience gained during the
internship period at Genus Electrotech Ltd. The report begins with an introduction to PCBs,
detailing their importance in modern electronics and their role as the foundational component
for electronic devices.

The main body of the report discusses the various stages of PCB manufacturing encountered
during the internship, including design, fabrication, assembly, and testing. Key aspects covered
include CAD design software used for PCB layout, selection of materials, understanding
manufacturing tolerances, and quality control procedures implemented to ensure reliability and
performance.

ⅲ
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

List of Figure

Fig 2.1 Shearing Machine……………………………………………………………………18

Fig 2.2 Corner Rounding Machine………………………………………………………......18

Fig 2.3 Beveling Machine……………………………………………………………………18

Fig 2.4 CNC Drilling Machine………………………………………………………………19

Fig 2.5 PCB Brushing Machine……………………………………………………………...21

Fig 2.6 Brushing Process…………………………………………………………………….22

Fig 2.7 Dry Film Photoresist Laminator……………………………………………………..23

Fig 2.8 UV LED Exposure Machine…………………………………………………………23

Fig 2.9 HAL Machine………………………………………………………………………..26

Fig 2.10 Legend Printing Machine…………………………………………………………..27

Fig 2.11 Legend Printing…………………………………………………………………….27

Fig 2.12 V-cut or Scoring Machine…………………………………………………………..28

Fig 2.13 CNC Routing Machine……………………………………………………………..29

Fig 2.14 BBT Testing Machine………………………………………………………………30

ⅳ
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

Table of Contents

Acknowledgement………………………………………………………...…………………ⅱ

Abstract………………………………………………………………………………………ⅲ

List of Figures………………………………………………………………………………..ⅳ

Table of Contents…………………………………………………………………………….ⅴ

About Company Profile……………………………………………………………………...ⅵ

Chapter 1 INTRODUCTION………….……..…………………………………….………1
1.1 INTRODUCTION OF PRINTRD CIRCUIT BOARD (PCB)……….……..1
Chapter 2 PCB MANUFACTURING PROCESS…………………………………...…….2
2.1 PPC……………………………………………………………………...……...8
2.2 SHEARING & CNC DRILLING……………………………………...……..9
2.3 PTH……………………………………………………………………………12
2.4 PIT……………………………………………………………………………..14
2.5 ETCHING……………………………………………………………………..15
2.6 PISM…………………………………………………………………………...16
2.7 HAL……………………………………………………………………………17
2.8 LP……………………………………………………………………………...18
2.9 V-CUT & ROUTING……………………………………………...…………19
2.10 BBT…………………………………………………………………………..21
2.11 FQC…………………………………………………………………………..23
2.12 PACKING & STORAGE…………………………………………………...24
Chapter 3 CONCLUSION…………………………………………………………………25
REFERENNCES…………………………………………………………………..……….26

ⅴ
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

COMPANY PROFILE

Genus Electrotech Ltd., a Part of the ‘Kailash Group’, is an ISO9001: 2000, 14001:2004 UL
& BIS certified & TS under certification.

Genus Electrotech Ltd, has proved itself as the first Indian venture having total backward
integration, right from bare board PCB to corrugation / EPS (Thermocol) for manufacturing
of all types of consumer electronics, IT, Automobile and communication products.

Genus Electrotech Ltd, is one of the fastest emerging company in the electrical/electronics
sector in india. We have a modern manufacturing plant with a dedicated team of
professionals, engineers and skilled operators. The variety and change that is prevalent in a
manufacturing facility is easily managed, enabling a diverse mix of products to be
manufactured and shipped to all corners of the world.

Genus Electrotech Ltd, is located at Gandhidham, Taluka Anjar, Dist. Kutch, Gujarat, with
the facilities spread over an area of 72,000 square meters.

Our Group moves with the belief that there are no dead ends, only beginnings. With this
spirit, today our group having the brand name ‘GENUS’ has a turnover of more than 400
Million USD.

Our culture is of absolute devotion to the customer, always acting with sincerity and honesty,
producing outstanding quality products and services, and providing our customers with the
best value for money.

ⅵ
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

CHAPTER-1
INTRODUCTION OF PRINTED CIRCUIT BOARD (PCB)

A printed circuit board (PCB) mechanically supports and electrically connects electronic
components using conductive tracks, pads and other features etched from copper sheets
laminated onto a non-conductive substrate.
PCBs can be single sided (one copper layer), double sided (two copper layers) or multi-layer
(outer and inner layers). Multi-layer PCBs allow for much higher component density.
Conductors on different layers are connected with plated-through holes called vias. Advanced
PCBs may contain components – capacitors, resistors or active devices – embedded in the
substrate.
Printed circuit boards are used in all but the simplest electronic products. Alternatives to PCBs
include wire wrap and point-to-point construction. PCBs require the additional design effort to
lay out the circuit, but manufacturing and assembly can be automated. Manufacturing circuits
with PCBs is cheaper and faster than with other wiring methods as components are mounted
and wired with one single part. Furthermore, operator wiring errors are eliminated.
When the board has only copper connections and no embedded components, it is more
correctly called a printed wiring board (PWB) or etched wiring board. Although more accurate,
the term printed wiring board has fallen into disuse. A PCB populated with electronic
components is called a printed circuit assembly (PCA). The IPC preferred term for assembled
board is circuit card assembly (CCA) and for assembled backplanes it is backplane assemblies.
The term PCB is used informally both for bare and assembled boards.

1
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

CHAPTER-2
PCB MANUFACTURING PROCESS
• PCB MANUFACTURING CONSISTS OF FOLLOWING STEPS:

Processes Process Name

1.

OK

2. NOT OK

OK

3.

OK

4.

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 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

OK

5.

OK

6.
OK

7.
OK

8. OK

OK
9.

NOT OK

10.

3
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

OK

11.

OK

12.

OK

13.

OK

14.

OK

15.

4
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

16. NOT OK

OK

17.

OK

18.

OK

NOT OK
19.

OK

20.

OK

21.

OK

5
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

22.

OK

23.

OK

24.

OK

25.
OK

26.

OK

27.
OK

28.

6
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

OK

29.

OK

30.

OK

31.

OK

32.

OK

33.

OK

34.

7
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.1: PRODUCTION PLANNING & CONTROL (PPC)

Production planning is one part of production planning & control dealing with basic concepts
of what to produce, when to produce, how much to produce, etc. It involves taking a long-term
view at overall production planning. Therefore, objectives of production planning are as
follows:
• To ensure right quantity and quality of raw material, equipment, etc. are available
during times of production.
• To ensure capacity utilization is in tune with forecast demand at all the time.

Production control looks to utilize different type of control techniques to achieve optimum
performance out of the production system as to achieve overall production planning targets.
Therefore, objectives of production control are as follows:

• Regulate inventory management

• Organize the production schedules
• Optimum utilization of resources and production process

The advantages of production control are as follows:

• Ensure a smooth flow of all production processes
• Ensure production cost savings thereby improving the bottom line
• Control wastage of resources
• It maintains standard of quality through the production life cycle.

Production planning is required for scheduling, dispatch, inspection, quality management,

inventory management, supply management and equipment management. Production control
ensures that production team can achieve required production target, optimum utilization of
resources, quality management and cost savings.

8
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.2: SHEARING & CNC DRILLING

Fig: 2.1 Shearing Machine

In shearing process, we use laminate sheets for the pcb pane. We cut these sheet according to
customer requirement. We use a machine for cut these laminate sheets, this machine is known
as Shearing Machine. For this process, we put the sheets in to the machine according to scale
in mm parameter. This machine cut the sheets in require size parts. The surface of these parts
are rough.

Fig: 2.2 Corner Rounding Machine Fig: 2.3 Beveling Machine

9
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

After cutting into required size, using corner rounding machine we round the corner of the
panel.
Next panel is going to the EBM (Edge Beveling Machine), here edges of panels are beveling.
Beveling means edge of the panel cut to slope on the surface from both the side. The application
for beveling is not just for aesthetic purposes but is often utilized for safety, wear resistance,
or to facilitate the joining of one piece with another.

CNC DRILLING:
After cutting in the shearing machine, these parts are called panels.
In brushing, we remove the remaining rough space on the panel.Then we put these panels in
the oven at 140’C temperature for 2 hours. This process is done for the better quality.
In Pinning process, the panel is put on the pinning machine and make the hole on both surface
of the panel. The diameter of the hole is 3.15mm. we can make hole in maximum 4 panels at
one time.
For drilling, we make a stack. Stack is a combination of one aluminium entry sheet, four
laminate panels and one back up panel (card wood sheet). Entry and back up panel are used
for the perfect drilling, Back up panel is used to protect from hole damage.
We apply a program of numerical control programming in the software of cnc drilling machine.
This operates automatically.
In drilling, we also drill machine number, operator code and part number. Drilling machine is
operated by air. The air pressure is 100-120 PSI. DLR (Diameter, Length, Run out on check)
is used in the drilling machine.

Fig: 2.4 CNC Drilling Machine

10
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

Drilling machines are also used for making the MICRO-200 ZIG and UTRON ZIG for Bear
Board Testing (BBT).
After drilling, we do depinning in which we remove the pins from the panels. Entry panel is
thrown the scrap and back up panel is reuse.

We find the drilling defects by using Myler. The drilling defects are following:-
• Over size hole
• Half drill
• Missing hole
• Shifting hole
• Under size hole
• Extra hole

These drilling defects are remove by the rework process.

11
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(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.3: PTH (PLATE THROUGH HOLE)

PTH Processs in PCB manufacturing is used to make the holes electroless after drilling. In this
process we remove the extra material from the holes and after this holes are useful to pass the
current.
PTH (plated through holes), additional steps of electroless deposition are done after the holes
are drilled, then copper is electroplated to build up the thickness, the boards are screened, and
plated with metal. The metal becomes the resist leaving the bare copper to be etched away.

In this process we use many baths and this is a auto process. There are following steps in this
process:
• BRUSHING

Fig: 2.5 PCB Brushing Machine

Brushing is done for removing the extra material from the pcb panels. In this at first we
load the panels to the cleaner, where panels should cleaned. Then we are used two water
baths for cleaning. After this we pass the panels through the micro etch bath where
sulphuric acid and hydrogen paroxide chemicals are used in the bath. This bath is used
for removing the extra copper from the holes. Then again pass this panels from two
water baths for cleaning. Then dip the panels in pre-dip bath and pass then from the
activater for activate the panels. And pass again panels from the two water baths for
perfect cleaning. To reduce the extra material from the panels we pass them from the
reducer bath and for polish the copper in the panels we pass from the two copper baths
and then from water baths.

12
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

Scrubbing Mid pressure rinsing Pressure rinsing

Blowing Squeezing City water rinsing

Drying Unloading panel

Fig 2.6: Brushing process

Following parameters are used in the brushing process:

• Upper brush current – 1.8-2.5 amp
• Lower brush current – 1.8-2.5 amp
• Temp. in dryer – 60-70’C
• Conveyer speed – 1.2-2.5 m/min
• Water pressure – 200-300 PSI

After brushing, we pass the panels through the PTH bath where PTH process is performed.
Then these panels are ready for the PIT (Photo Image Transfer).

13
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.4: PIT (PHOTO IMAGE TRANSFER):-

Fig: 2.7 Dry film photoresist laminator Fig: 2.8 UV led exposure machine

Photo image transfer is mainly used for laminating the pcb panel and transfer the circuit
image on pcb panel. We perform the PIT process in three simple steps:
• Laminating
• Exposing
• Developing
We use laser photoplotters in a temperature and humidity-controlled darkroom to make the
films we will use later to image the PCBs. The photoplotter takes the board data and converts
it into a pixel image. A laser writes this onto the film. The exposed film is automatically
developed and unloaded for the operator.
For laminate the pcb panels, we use a dry film which temperature is 90-110’C. We use two
types of laminators for laminating the pcb panels:-
• OTS Laminator
• Riston Laminator
After laminating the pcb panels, we pass these through the exposing machine. For exposing
we use a myler, which protects the pcb panel from scratching. In this, we transfer the image of
the circuit on the pcb board and makes the dry film hard on the circuit lines.
After exposing, we pass the panel through the developing machine. In which we use a chemical
which is Sodium Carbonate. This chemical is used for removing the soft dry film where the
circuit components are not designed and remaining hard dry film are safe.
Then the panels are ready for the plating and etching process.

14
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.5: ETCHING:-

The panel is ready for the etching after the plating process performed on the panel. In etching
process we use three machine:-
• Dry film stripper machine
• Etching machine
• Tin stripper machine
In dry film stripper machine, we remove the dry film which is remaining after the plating. The
temperature is maintained 48-55’C. We use a 500Lit. chemical bath for this process. The water
pressure is 25 PSI.

After dry film stripper process, the panel are passing through the etching machine. In etching,
we remove the extra copper from the panel. We remove almost 30-40% copper from the panel.
This removed copper is stored in the chemical bath. We use chiller in the etching process for
decreasing the temperature when the temperature is being high in the machine.

Etching is traditionally the process of using strong acid or mordant to cut into the unprotected
parts of a metal surface to create a design in intaglio in the metal.

After etching process we pass these panels from TIN stripping machine where we remove tin
from the panel. For this process we use a 400 Lit. chemical bath in which we use rbp chemical.
We use RO water and normal water for cleaning.

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 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.6: PISM (PHOTO IMAGE SOLDER MASK):-

The pcb panels is ready forPISM process after completing the etching process. Photo-
imageable solder mask is a contact exposure photo-imageable solder mask for aqueous
developing. It is formulated for use on high density copper, black oxide or tin/lead plated
printed circuit boards where the required definition cannot be achieved with conventional
screen printable resists. In PISM, we perform a coating of green colour film on the pcb plate.
In PISM following steps are follow:
• Brushing
• Printing process
• Pre-backing process
• Exposing
• Developing
In brushing we remove the extra dust from the panel and clean the pcb plate. For squeezing we
use spunze rollers. And use lower brush and upper brush in the scrubbing bath. In brushing
we remove 8-15 micron copper from the panel. We use a chemical for cleaning process, the
chemical mixture is 5% sulphuric acid + 95% DI water. We put the drying temp. is 65-70’. The
lower and upper brush current is 2-2.8 Amp.
In Printing process, we use a printing machine for green colour ink coating on the panel. The
machine is operated on 2.5-3.5 kg/cm3 air pressure. We use extra ink for the coating. The
thickness of the coating is 30-35 micron. Coating is used for removing the leakage current and
protect short circuit. We use a skin between the panel and ink where 55 threads in 1mm skin.
After printing we put the panel into the oven for 50min, where the temp. is 72’C. this process
is called Pre-Backing Process. After pre-backing we pass the panel through the exposing
machine. In exposing machine we use a film, which makes the space hard black for the
soldering. The remaining space is blank. We mainly use UV exploser machine. There are two
8KW light lamp in the machine. When we put the panel in the machine, then light fall on the
panel. The soldering space making soft and other remaining space is makes hard. The hard part
can’t be removed. Then we send the panel in the developing machine
In developing machine we use a chemical developer bath. The chemical is 5% sodium
carbonate + 95% water. This sodium carbonate is used to remove the soft ink, which is used
for the soldering. After PISM we do the final backing at 150’C temp. for 90min.

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 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.7: HAL (HOT AIR LEVELING):-

After final backing, we do the HAL process on the panel. In HAL, we do pre-cleaning and post
cleaning for the soldering. In this, we solder the space where the components posted. The PCB
is typically dipped into a bath of molten solder so that all exposed copper surfaces are covered
by solder. Excess solder is removed by passing the PCB between hot air knives.
HAL provides a very reliable solder joint and shelf life. HASL makes component soldering
very effective. But due to the thickness of HASL coating, the polarity of the surface can be
unsuitable for fine-pitch components.
Pre-cleaning process, The copper to be covered with tin alloy is activated with the help of
mild acid cleaner. This removes oxides from the surface of the copper.
Flux, Flux is applied to prevent further oxidation and to create the right conditions for the
application of the solder.
Dipping, The panel is dipped in the melt and any excess solder is blown away with the help of
a flow of hot air applied by hot air knives at a high pressure. This also ensures that the deposits
are of an even thickness.
Post-cleaning process, Removes the flux by washing it in hot water. At this point is then ready
for mechanical treatment.

Fig: 2.9 HAL Machine

17
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.8: LEGEND PRINTING:-

Fig: 2.10 Legend Printing Machine

The pcb panel is ready for the LP after the HAL process. Legend printing is performed for the
marking, where the components are tested. We use a legend printing machine for marking. We
use a KSM 388 THERMAL INK of white colour for the printing.
We use Butyl cello solve for cleaning the wrong printing.
After printing we put the panel in the oven at temp, 145’C for 20 min.
Printing machine is operated by the air valve of 8kg/cm2. After LP we pass through the UV
curing to make hard the white print. There are three 1800 watt lamps in the UV curing. Then
the panel is ready for the v-cut or routing.

Fig: 2.11 Legend printing

18
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.9: V-CUT & ROUTING:-

V-CUT:-
In V-cutting process, we draw a v-shape cut on both sides of the pcb panel. The
minimum distance between any two V-cut lines is 5.00 mm.
Panels with V-cut do not necessarily need a panel border to create mechanical stability.
The panel border on V-cut panels is mainly for ease of handling during the assembly process
(tooling holes, fiducials). We use 1.6mm thickness panel for pcb manufacturing and we cut
0.6mm both sides on the panel and 0.4mm material will remain.
The angle of the V-shape is 30’. V-cut is always over the complete lengh of the panel
(no jump scoring). This means that only square or rectangular PCB’s of the same size can be
panelized when V-cut is the only board separation method chosen. It is however possible to
use V-cut on irregular shaped PCB’s when used in combination with extra milling or even
break-routing to obtain the desired PCB shape. In such cases you may need to add extra
clearance between the PCB’s to provide “run-out” space for the milling or break-out-router.
There are two types of v-cutting which are following:-
• CNC V-CUTTING
• MANUAL V-CUTTING
In CNC v-grooming machine, we set the coordinates of v-cut through the program in CAT-
CAM 350 software. This is a automatic machine.
If there are 2.4mm thickness panel then the remaining thickness after the v-cut is 0.5mm, if
thickness is 1.6mm, then remaining is 0.4mm, if thickness is 1mm then remaining is 0.3mm,
if thickness is 0.8mm then remaining is 0.3mm. then is send for the ROUTING process.

Fig: 2.12 V-cut or scroring machine

19
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

ROUTING:-

The final step to complete your PCB order is to remove each board from the larger
panel upon which it was fabricated. Depending on the method of assembly and the partner
chosen for assembly, one of this three options will meet your need.
In routing, we mainly cut the panel in to small parts of pcb. We also use CAT-CAM
350 software in routing machine same as V-cutting machine. We take the outer hole of the
panel as reference hole. The cutting space is measured according to reference hole distance.
We use MEGA 4500 and MEGA 4600 machine for the routing and drilling. The speed is main
deference between MEGA 4500 and MEGA 4600. The vaccum pressure in the machine is 100-
200 PSI. and maintain the room temp. at 20-24’C.
Then we clean the panels and the panel is ready for the BBT (Beare Board Testing).

Fig: 2.13 CNC Routing machine

20
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.10: BBT (Bare Board Testing):-

Fig: 2.14 BBT testing machine

Panels are ready for the electrical testing after v-cutting and routing. Unpopulated boards are
usually bare board tested for “shorts” and “opens”. A short is a connection between two points
that should not be connected. An open is a missing connection between points that should be
connected. For high-volume production a fixture or a rigid needle adapter is used to make
contact with copper lands on the board. Building the adapter is a significant fixed cost and is
only economical for high-volume or high-value production. For small or medium volume
production flying probe testers are used where test probes are moved over the board by an XY
drive to make contact with the copper lands.
The CAM system instructs the electrical tester to apply a voltage to each contact point as
required and to check that this voltage appears on the appropriate contact points and only on
these.
There are three machines are mainly used for the electrical testing:-
• MICRO-200
• UTRON
• ATG
We make a ZIG in by the drilling machine for electrical testing. The panel is put between the
two parts of the ZIG.

21
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

We currently have two different types of testing equipment available to test your circuit boards;
we have a number of Everett Charles ATG test machines that are flying probe, fixtureless
testers and we also have universal grid testing capability. These machines use fixtures built
specifically for your PCB.
Bare board testing involves using capacitance and resistance tests; each of our machines uses
a combination of both. Capacitance testing for a bare board involves testing for opens and
shorts by “charging” a net or plane and then probing each net to measure the induced capacity.
Resistance testing measures the resistance found in the net. As electric current flows through a
conductor collisions between electrons and atoms interfere with the flow of the electrons. This
is known as resistance and it’s measured in ohms.
A good conductor has LOW resistance- at common temperatures silver is the best conductor
and copper is second. The amount of resistance depends on the conductor’s length and its cross-
sectional area. If you have two circuits of the same material and the same cross-section and
one is twice as long as the other- the longer one has TWICE as much resistance. If you have
two circuits of the same material and the same length but one is twice as thick as the other- the
thicker conductor will have HALF the resistance.
So resistance is proportional to length and inversely proportional to the cross-sectional area of
a conductor and dissipates power in the form of heat.

22
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.11: FQC:-

FQC is FINAL QUALITY CONTROL PROCESS, in which we inspect the whole panel after
manufacturing process. The panel is ready for FQC after the BBT.
There are following two types of inspection stage:-
• HOLE Inspection Stage
• FINAL Inspection Stage
HOLE INSPECTION STAGE:-
• Void
• MIP
• Half hole
• Missing hole
• Tent break
• 2nd stage missing
• Half routing
FINAL INSPECTION STAGE:-
• Customer name
• Part no.
• Batch no.
• Company logo
• Legend printing
• Routing
• NPTH slots
• V-cut depth
• HAL surface
• Solder mask surface
• BBT sticker
The report book of the pcb panel also ready in this section.

23
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

2.12: PACKING & STORAGE:-

After BBT & FQC the panel is ready for packing. There are following stages in the packing:-
• Warp edge stage:-
In warp edge, we check the corners of the pcb panel. The problem of warp edge will remove
in the curing where temp. is 250’C for 2hours.
• We check the bar code on the panel which is printed in the legend printing.

• Counting:-
We count the panel according to the weight. Mainly we count 24 panels at one time. We
check panels randomly.
• Vaccum packing:-
For vaccum packing we use a vaccum machine. For packing process we use polythene role
and rubber role. This is a automatic machine.
Then we pack them in cartoon box and paste a list according to customer requirement. The
list may contain following parts:-
I. Date of order
II. Part no.
III. Quantity
IV. Week code
V. Box no.

After packing the panels are ready for dispatch. We store these boxes in a room till
dispatching.

24
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

CHAPTER – 3
CONCLUSION

As an undergraduate of the Gujarat Technological University. I would like to say that

this training program is an excellent opportunity for us to get to the ground level and experience
the things that we would have never gained through going straight into a job. I am grateful to
the GENUS ELECTROTECH LTD. for giving us this wonderful opportunity.
The main objective of the industrial training is to provide an opportunity to under
graduates to identify, observe and practice how engineering is applicable in the real industry.
It is not only to get experience on technical practice but also to observe management practices
and to interact with fellow workers.
The only chance that an undergraduate has to have this experience is the industrial
training period. I feel I got the maximum out of that experience. Also I learnt the way of work
in an organization, the importance of being punctual, the importance of maximum
commitment, and the importance of team sprit
The training program having three destinations was a lot more useful than staying at
oneplace throughout the whole two weeks.

25
 GUJARAT TECHNOLOGICAL UNIVERSITY
(Established under Gujarat Act No. 20 of 2007)
ગુજરાત ટે કનોલોજીકલ યુનનવનસિટી
(ગુજરાત અધિધિયમ ક્રમાાંક: 20/2007 દ્વારા સ્થાધિત)

REFERENCES:

• https://www.iitk.ac.in/ee/data/pcb/pcb-lab.pdf
• https://www.pcbelec.com/pcb-fabrication-process.html
• https://www.ncabgroup.com/wp-
content/uploads/2016/12/NCAB_production_process_how_to_make_a_PCB.pdf
• https://www.researchgate.net/publication/344229739_Printed_Circuit_Board_M
anufacturing
• https://www.protoexpress.com/kb/pcb-manufacturing-overview/

THANK YOU

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