Assembling electronic products_jomar marfil

WEB SCRIPT Electrical and Electronics
Sector: Electronics Products Assembly and Servicing NC II
Qualification: Assemble Electronic Products
Unit of Competency: Assembling Electronic Products
Module Title: LO1: Prepare to Assemble Electronic products
Learning Outcomes: Jomar Marfil
Developer/s:
TITLE Preparing to Assemble Electronic products
OBJECTIVES After this lesson the learners will be able to control risk while assembling,
Topic 1 identify the different ESD damage, identify the components of a power
supply and create a diagram of power supply.
INTRODUCTION Risk control measures in Assembling Electronic Products

Lesson 1 Risk control is a step in the hazard management process. It involves
finding a way to neutralize or reduce an identified risk.

In many cases, a controlled risk is still a potential threat to employees,
but the dangers associated with it have been significantly reduced.

Risk control is also known as hazard control.

Source: https://www.safeopedia.com/
ESD

A crackling sweater, hair that sticks straight out from your head, a small electric shock from a door
handle. We are all familiar with those moments when there is a discharge of static electricity; this
phenomenon is known as Electrostatic discharge (ESD).

ESD often occurs in very common everyday situations like when walking on a carpet in plastic-
soled shoes. When this happens, mainly negative electrical charges are picked up and distributed
across the entire surface of the object or body. If contact is then made with another conductive

body or with ground, this charge suddenly flows off. Depending on the number of voltages involved
it will be possible to feel, hear and see this phenomenon in the form of a spark or a flash.

Voltages of over 10,000 volts can easily arise in modern workplaces and although this would pose
no danger to people it could mean the end for electronic devices. Plastics in particular are very
susceptible to electrostatic charging due to their high surface resistance. The surface potential of a
normal plastic box is anywhere up to 20,000 volts, a dangerous environment for any electronic
devices transported inside it.

1.1 Types of ESD Device Damage

As the electronics industry becomes more technologically advanced, the electronic components
become smaller and compact thus, becoming more sensitive to ESD.
The extremely thin conducting paths in active electronic components like IC’s are often unable to
withstand the high ESD voltages involved. Some of the damage sustained is visible but some can
only be seen under an electron microscope. These different types of damage are referred to as
direct faults and latent faults.

Direct Faults
30% of ESD damages are direct faults, or also known as catastrophic failures. These are types of
damages that are usually visible and what usually renders the component completely useless.
In most cases, normal inspection is enough to identify and point out direct faults.

Latent Faults
70% of ESD damages around the world are latent faults, or also known as intrinsic faults. These
are not visible to the naked eye and don’t usually harm or damage the component immediately.
Most of the time, failures happen when the component is in use or in operation. When such
damages kick in, severe consequences happen and may affect other components.
Sources: https://technofaq.org/posts/2018/05/understanding-the-nature-of-how-esd-damages-your-components/

https://www.rtpcompany.com/products/conductive/the-danger-of-esd/
https://www.wikihow.com/Ground-Yourself-to-Avoid-Destroying-a-Computer-with-Electrostatic-Discharge
Quiz 1: H5P Hotspot

1. Which one of these pictures is a Latent fault caused by ESD?

2. Which one of these pictures is a Direct fault caused by ESD?

Lesson 2 Risk control measures

Understanding how to create and perform a job is important. However, it is more important to know
and understand the risk control measures in order to prevent or reduce the chances that any of the
learners will be injured on the job, or to reduce the chances that anything they make or done will
cause harm to the community. Power supply is an electronic device which is very dangerous to
every learner because it deals with electrical current, voltage, power, and energy quantities that
should be handled with extreme diligence and care.

2.1 Common Safety Precaution in Electronic devices

Safety Signs are crucial in any work environment. The primary importance of displaying Safety
Signs is to prevent injury and ensure users are well aware of the possible dangers and hazards
ahead in certain situations and/or environments. Without signs, many employees would lack the

necessary direction in times of crisis, and employers might find themselves in significant legal
difficulties if any accidents were to arise as a result.

This is the universal warning or caution symbol. This symbol is mostly used to express potential
danger.

This symbol warns the user to take precautions in disassembling, modifying, or repairing the
electronic product.

This symbol warns the user to take precautions in touching the terminals while the power is being
supplied. It may cause minor injury due to electric shock.

This symbol warns the user to take precautions in touching the electronic product while the power
is being supplied or immediately after the power is turned off. It may cause minor burns.

This symbol warns the user of probable danger of minor electric shock, fire or possible product failure.
2.2 Precautions for Electronic Products Assembly

Input voltage

Using a commercial power supply for the supply voltage input models with AC inputs.
Inverters with an output frequency 50/60 Hz are available, but the rise in the internal temperature of
the power supply may result in ignition or burning.

Grounding
Connecting the ground completely may avoid the electric shock.

Mounting
The installation screws can be tightened into the power supply only to a limited depth. Make sure
that the lengths of the screws protruding into the power supply are within the specified dimensions.
Source: http://www.ia.omron.com/product/cautions/22/safety_precautions.html
Quiz 2:Hotspot

1. Which one of these symbols warns the user in taking precautions when
disassembling the unit?

2. Which one of these symbols warns the user in touching the unit for it might
cause electric shock?

3. Which one of these symbols warns the user in touching the unit for it might
cause minor burns?

VIDEO Hazards and Risks

Watch the video below to learn about hazards and risks.

https://www.youtube.com/watch?v=n_IPD1ZMXpA

Guide Questions:
1. How can you differentiate hazard to risk?
2. What are the things to consider in evaluating the risk?
3. How should you manage the risk?

Model Answer

1. How can you differentiate hazard to risk?

Hazard is the potential to cause hard, while risk is the likelihood of harm in defined circumstances.

2. What are the things to consider in evaluating the risk?

In evaluating the risk you have to consider on how, where, how much and how long you will be
exposed to the hazard because it can be calculated based on the frequency, conditions and length
of exposure.

3. How should you manage the risk?

Risk can be managed by limiting exposure to a danger by adoption of risk-reduction measures.

ACTIVITY SHEET 1

Title: Performing Risk Control Measure Evaluation

Performance Objective: Given the necessary equipment and supplies you should be able to
perform risk control measure evaluation.

Supplies / Materials: Bond Papers

Equipment: Desktop computer, Printer with Ink / Toner

Time Limit: 5 minutes

Steps/Procedure:

Given a list of hazards available when assembling electronic products, provide an answer for the
risks and its control measures.

After answering the risk control evaluation form, create a summary report using the questions below:
1. Cite another hazard, risk and its control measures involved in assembling electronic products.
2. As a learner, how can you reduce or prevent risk in performing different tasks in electronics?
3. If PPE was not present during assembling electronic products activity, what are the possible
risks that you may encounter?

Submit your summary report together with the risk control measure evaluation form to your learning
facilitator.

RISK CONTROL EVALUATION FORM

HAZARD RISK CONTROL
MEASURES

Used incorrect input voltage.
Input cable is connected to the wrong terminal.
Touching accidentally an energized power supply.
Touching accidentally a pre-heated soldering iron
Accidentally shorted the input terminal of a power
supply.

PERFORMANCE CRITERIA CHECKLIST
ACTIVITY SHEET 1

Learner’s Name: __________________________ Date: _______________

CRITERIA YES NO

Did my group... ?

1. fill up the risk control measure evaluation form completely
2. create a result summary using the guide questions
Learning facilitator’s Signature:

Comment/Feedback:

Topic 2 Power Supply
Lesson 1 Parts and Components

A power supply is an electronic circuit that converts an ac voltage to dc voltage. It is basically consisting of
the following elements: transformer, rectifier, filter and regulator circuits. Power supply units (PSU) are used
in computers, amateur radio transmitters and receivers, and all other electronic equipment that use dc
voltage as an input.
1.1 Transformer

The transformer is a static device that transfers electrical energy from the primary winding to the
secondary winding without affecting the frequency.
Three Main Functions of Transformer:

1. Stepping up the voltage up
2. Stepping the voltage down
3. Providing isolation between the primary and secondary circuits
1.2 Rectifier (Bridge Rectifier Diode)

The rectifier is a device used to change the ac power into pulsating dc. The basic rectifier is the
diode.

1.3 Filter (Capacitor and Resistor)

The filter of the power supply is used to keep the ripple component from appearing in the output. It
is designed to convert pulsating DC from rectifier circuits into a suitably smooth dc level.
1.4 Voltage Regulators

A voltage regulator is designed to provide a very steady or well regulated dc output. It is always
ideal to have a steady output voltage so that the load will operate properly. The output level is
maintained regardless of the variation of the input voltage. The commonly used transistor voltage
regulators are the series voltage regulator and the shunt voltage regulator.
Source:
https://turbofuture.com/industrial/Basic-Elements-of-a-Power-Supply
https://forum.allaboutcircuits.com/threads/submission-power-supply-circuits.33444/
Quiz 3: H5P Flash cards

It is an electronic circuit It is a static device that It is a device used to

that converts an ac voltage transfers electrical energy change the ac power into

to dc voltage. from the primary winding to pulsating dc. The basic

the secondary winding rectifier is the diode.

without affecting the

frequency.

It is designed to convert pulsating DC from It is designed to provide a very steady
rectifier circuits into a suitably smooth dc or well regulated dc output.
level.

ASSIGNMENT SHEET 1
Title: Constructing an Unregulated Power Supply Schematic Diagram
Performance Objective: Given the necessary supplies you should be able to construct an
unregulated power supply schematic diagram.
Supplies / Materials: Bond papers
Time Limit: 5 minutes
Steps/Procedure:

1. Outline the system of a power supply.
Create a block diagram of the system from input to
its output to better understand the flow of the
system.

2. Disregard unnecessary components.
By understanding the task, the activity requires an
unregulated power supply schematic diagram
meaning that a regulator is not included.

3. Recall and assess basic circuit components
and symbols.
Scan over from your previous lessons about
different electrical and electronic symbols and apply
the necessary symbols in a schematic diagram .

4. Start by drawing the symbol of the input and
work your way to the components and output.
Add fuse or switch if the schematic diagram
requires one.

5. Draw the transformer.
Depending on the requirement of the schematic
diagram, the transformer can be single output or
multi - output.

6. Draw the rectifier.
A rectifier is a bridge network of rectifier diodes.

7. Draw the rest of the components.
The RC filter is a combination of a capacitor and a
resistor connected in parallel. Don’t forget to
indicate the + and - signs to indicate a DC output.

8. Indicate the label for each symbol.
Review the schematic diagram for the short circuit.

Assignment 1

Direction:
Given the fundamental steps in creating a schematic diagram of an unregulated power supply, you
are required to

• construct a schematic diagram of an unregulated power supply by following the given
guidelines below and

• afterwards attach the presentation through an e-mail to your learning facilitator.

Construct an unregulated power supply schematic diagram using the following components:
Note:

• Indicate (1) one output and (1) one input voltage
• Indicate the component code

1. AC Source 5. Rectifier Diode
2. Fuse 6. Capacitor
3. Switch 7. Resistor
4. Step down Transformer 8. Light Emitting Diode

PERFORMANCE CRITERIA CHECKLIST

ASSIGNMENT SHEET 1

Learner’s Name: __________________________ Date: _______________

CRITERIA YES NO

Did I... ?

1. construct a schematic diagram of an unregulated power supply by following the
guidelines

2. indicate the input and output voltage

3. include component code or label

4. attach the document through an email to my learning facilitator
Learning facilitator’s Signature:

Comment/Feedback:

WEB SCRIPT Electrical and Electronics
Sector: Electronics Products Assembly and Servicing NC II
Qualification: Assemble Electronic Products
Unit of Competency: Assembling Electronic Products
Module Title: LO2: Prepare/ Make PCB modules
Learning Outcomes: Malvin Marquez
Developer/s:

TITLE Preparing/ Making PCB modules
OBJECTIVES
At the end of the lesson the learners will be able to
INTRODUCTION Printed circuit board is the support and connection between electronic
components and it is important to know the characteristics and how to
Topic 3 fabricate PCB.
INTRO
Printed Circuit Board (PBC)

PCB Overview

PCB is a copper laminated and non-conductive Printed Circuit Board, in which all electrical and
electronic components are connected together in one common board with physical support for all
components with base of board. When PCB is not developed, at that time all components are
connected with a wire which increases complexity and decreases reliability of the circuit, by this
way we cannot make a very large circuit like motherboard. In PCB, all components are connected
without wires, all components are connected internally, so it will reduce the complexity of the overall
circuit design. PCB is used to provide electricity and connectivity between the components, by
which it functions the way it was designed. PCBs can be customised for any specifications to user
requirements. It can be found in many electronics devices like; TV, Mobile, Digital camera,
Computers parts like; Graphic cards, Motherboard, etc. It is also used in many fields like; medical
devices, industrial machinery, automotive industries, lighting, etc.

There are several types of PCB available for the circuit. Out of these types of PCB, we have to
choose the appropriate type of PCB according to our application.

3.1 Types of PCB according to Application

Single Layer PCB
A single layer PCB is also known as single sided PCB. This type of PCB is simple and most used
because these PCBs are easy to design and manufacture. One side of this PCB is coated with a

layer of any conducting material. Generally, copper is used as conducting material for PCB,
because copper has very good conducting characteristics. A layer of solder mask is used to protect
PCB against oxidation followed by silk screen to mark out all of the components on the PCB.

Double Layer PCB
Double layer PCB is also known as double sided PCB. As the name suggests, in this type of PCB,
a thin layer of conducting material, like copper is applied to both top and bottom sides of the board.
In PCB, on different layers of board, consist via, which has two pads in corresponding positions on
different layers. These are electrically connected by a hole through the board.

Multi-Layer PCB
Multilayer PCB has more than two layers. It means that this type of PCB has at least three
conductive layers of copper. For securing the board glue is sandwiched between the layers of
insulation which ensures that the excess heat will not damage any component of the circuit. This
type PCB designing is very complex and used in very complicated and large electrical tasks in very
low space and compact circuits.

Flexible PCB
Flexible PCB is also known as Flex circuit. This type of PCB used flexible plastic material like
polymide, PEEK (Polyether ether ketone) or transparent conductive polyester film. The circuit board
is generally placed in folded or twisted.

Rigid PCB
Rigid PCBs are made out of solid materials which don’t allow PCB from twisting. Same as flex
PCB, Rigid PCB also has different layer configurations like single layer, double layer and multi-layer
Rigid PCB. Shape of this PCB is not changed after installation. This PCB cannot be bent according
to the shape of base that’s why this PCB is known as RIGID PCB.

Flex-rigid PCB
Combination of Flexible circuit and rigid circuit is the most important board. Flex-rigid boards
consist of multiple layers of flexible PCB attached to a number of rigid PCB layers.
3.2 Types of PCBs According to Mounting System

Through-hole PCB

In this type of PCB, we have to make hole using a drill on the PCB. In these holes, leads of
components are mounted and soldered to pads situated on opposite sides of PCB. This technology
is most useful because it gives more mechanical support to electrical components and very reliable
technology for mounting of components but drilling in PCB makes it more expensive. In single layer
PCB, this mounting technology is easy to implement, but in case of double layer and multi-layer
PCB making holes is more difficult.

Surface mounted PCB

In this type of PCB, components are small in size because these components have very small lead
or no leads are required for mounting on the board. Here, in this technology, SMD components are
directly mounted on the surface of the board and not required to make hole on board.

Lesson 2 Parts of PCB

Pad
Pad is nothing but a piece of copper on which the lead of components are mounted and on which
soldering is done. Pad provides the mechanical support to the components.

Trace

In PCB, components are not connected with the help of wires. All components are connected with a
conducting material like copper. This copper part of PCB which is used to connect all components
is known as trace.

Layers
According to application, cost and available space of circuit, users can choose the layer of PCB.
Most simple in construction, easy to design and most useful in routine life is single layer PCB. But
for very large and complex circuits, double layer PCB or Multi-layer PCB is most preferred
compared to single layer PCB.

Silk layer
Silk layer is used for printing lines, text or any art on the surface of a PCB. Usually, for screen
printing epoxy ink is used. Silk layer can be used in the top and/or bottom layer of PCB according to
user requirement which is known as silk screen TOP and silk screen BOTTOM.

Top and bottom layer
In Top layer of the PCB, all components are mounted in this layer of PCB. Generally, this layer is
green coloured. In the bottom layer of PCB, all components are soldered through the hole and lead
of components is known as bottom layer of PCB. Sometimes, the top and/or bottom layer PCB is
coated with a green colour layer, which is known as a solder mask.

Solder Mask
There is one additional layer on the top of the copper layer called the Solder Mask. This layer
generally has green color but it can be of any color. This insulating layer is used for to prevent
accidental contact of pads with other conductive material on PCB.

Quiz 4:

Topic 4 PCB Preparation

Lesson 1 PCB Designing

How to properly design/layout a Printed Circuit Board (PCB)

Make important nodes accessible:
It will eventually happen that you are trying to figure out why something is not working and you want
to measure a signal inside your PCB.

Give space between components:
It is tempting to pack the components as close as possible, only to realize that there is no room for
the routing of wires. Give some space between components so that wires can spread. The more
pins the component has, the more space it will need. Spacing will not only facilitate auto-routing as
it will make soldering easier.

Place components with the same orientation:
Components generally have a standard pin numbering, with pin #1 in the upper-left corner. If all
components are oriented equally, you will not make mistakes when soldering or when inspecting a
component.

Print the layout to see if components' sizes match:

After laying out all the components, print out the layout. Place each component on top of the layout
paper to see if they match. Sometimes datasheets may have errors.

Exchange wiring directions between layers:
Draw vertical traces on one side and horizontal traces on the other. This facilitates wiring of lines
that have to cross over the others. For multiple layers, alternate between directions.

Select the width of lines depending on current:
Larger width reduces resistance, which in turn reduces the heat caused by dissipation. The width of
the lines should be sized according to the estimated current that flows through them.

Know the specifications of the manufacturer:
Each manufacturer has its own specifications, such as minimum trace width, spacing, number of
layers, etc.

Avoid 90º angles with traces:
Sharp right angle turns are difficult to keep the trace width constant. This is a reason of concern for
narrow traces, where a small difference makes a significant fraction of the trace. A better approach
is to do two 45º bends.

Use the silk layer:
This layer is pretty standard in professional PCB manufacturers and it is extremely useful for
labelling. Label your components (the PCB layout software usually does this) and add some
information regarding what the board is about, a revision number, and the author/owner.

Use the schematic vs. layout comparison:
Many PCB layout softwares have a comparison tool between schematic and layout. Use it to
guarantee that your layout is matching the schematic.

Create a ground plane:
Especially in analog circuits, it is important that "ground" means the same voltage throughout the
PCB. If you use traces to route the ground signal, their resistance will create voltage drops that will
make different "grounds" in the PCB have different potentials. To avoid that, you should create a
ground plane.

Place bypass capacitors:
Bypass capacitors are used to filter AC components from your constant power supply. They reduce
noise, ripples and other unwanted AC signals. They do so by bypassing these AC fluctuations to
ground, which gives them the name.

Route the differential signal traces in parallel:
Differential signals are often used to improve immunity to noise and amplify the dynamic range.
This is only effective if the traces of both signals follow similar paths, so that the noise disturbs both
paths equally.

Consider spots of heat:
Heat can degrade performance of circuits and even damage them, if not well dissipated. Consider
which components consume more power and how the heat produced is being diverted by the
package.

Lesson 2 PCB Fabrication

PCB Fabrication Procedure
Step1: Design the PCB Circuit with a Software
Draw the schematic circuit diagram with the PCB layout software such as CAD software, Eagle and
Multisim software.
Here we have selected Eagle software to design the circuit and its procedure is as follows:
a. Open the Eagle circuit board design software.
b. A window with a menu bar appears.
c. Click on the file menu.
d. Select ‘new design’ from the drop-down menu.
e. Click on the library menu.
f. Select ‘pick devices/symbol’ from the drop-down menu.
g. Select a relevant comment by double-clicking on it, so that the component appears on the
window.
h. Add all the components and draw the circuit with proper connections as shown in the figure.

i. Enter the rating of each component according to the requirement.
j. Go to Command Toolbar and click Text editor varriages, click on the Varriages, and then
close the window.
k. Next, a black screen appears which is of the layout or the film diagram of the circuit as
shown in the below figure, and save this as an image format.

Step2: Film generation
The film is generated from the finalized circuit board diagram of the PCB layout software which is
sent to the manufacturing unit where the negative image or mask is printed out on a plastic sheet.

Step3: Select Raw Material
The bulk of the printed circuit board is made with an unbreakable glass or fiberglass having copper
foil bonded onto one or both the sides of the board. Thus, the PCBs made from unbreakable paper
phenolic with a bonded copper foil are less expensive and are often used in household electrical
devices.

Step 4: Apply Image
The printed circuit layout can be printed in different ways on PCBs like a manual pen, dry transfers,
pen plotters, and printers. The laser printers are a better way to print the layouts on printed circuit
boards.

Step 5: Stripping and Etching
This process involves removing the unwired copper on the PCBs by using different types of
chemicals like ferric chloride, ammonium per-sulfate, etc. Make the solvent by mixing 1% of sodium
hydroxide and 10 grams of sodium hydroxide pellets to one liter of water and mix it until everything
is dissolved. Next, the PCB is put on a chemical bowl and cleaned up with a brush. during this
process, if the PCB is still greasy, due to applied sunflower or seed oil, the developing process may
take about 1 minute.

Step 6: Preparing Drill Holes
Machines and carbide drills are used to put holes on the printed circuit board.

Step7: Testing
After finishing the manufacturing process of the Printed Circuit Board, the Board undergoes a
testing process to check whether the PCB is working properly.

Quiz 5

WEB SCRIPT Electrical and Electronics
Sector: Electronics Products Assembly and Servicing NC II
Qualification: Assemble Electronic Products
Unit of Competency: Assembling Electronic Products
Module Title: LO3: Mount and solder electronic components
Learning Outcomes: Ma. Rose Perona
Developer/s:
Mounting and soldering electronic components
TITLE At the end of the lesson the learners will be able to mount and solder
OBJECTIVES electronic components.
Topic 5 Soldering
Soldering is a process in which two or more items (usually metal) are
INTRODUCTION joined together by melting and putting a filler metal (solder) into the joint,
the filler metal having a lower melting point than the adjoining metal.
Lesson 1
Guides and Techniques in Soldering/Desoldering

Sources: https://images.app.goo.gl/5j1NfVswxttH8kM77

https://images.app.goo.gl/mxeDpKtmiCajjTHg7

Soldering & Desoldering Techniques

A typical printed circuit board, or PCB, contains a large number of electronic components. These
components are held on the board by solder flux that creates a strong bond between the pins of a
component and their corresponding pads on the board. However, the main purpose of this solder is
to provide electrical connectivity. Soldering and desoldering is performed to install a component on
a PCB or to remove it from the board.
Soldering with Soldering Iron

Source:https://images.app.goo.gl/oVsn3xAbAgJmYHs47

A soldering iron is the most commonly used tool to solder components on PCBs. Generally, the iron
is heated to a temperature of about 420 degrees Celsius, which is enough to quickly melt the solder
flux. The component is then positioned on the PCB such that its pins are aligned with their
corresponding pads on the board. In the next step, the solder wire is brought into contact with the
interface between the first pin and its pad. Briefly touching this wire at the interface with the heated
soldering iron tip melts the solder. The molten solder flows on the pad and covers the component
pin. After solidifying, it creates a strong bond between the pin and the pad. Since the solidification
of the solder happens fairly quickly, within two to three seconds, one can move to the next pin
immediately after soldering one.

Reflow Soldering

Source: https://images.app.goo.gl/NLuhBW3DteUhWv6p7

Reflow soldering is generally used in PCB production environments in which large numbers of SMD
components need to be soldered at the same time. SMD stands for surface mount device and
refers to electronic components that are much smaller in size than their through-hole counterparts.
These components are soldered on the component side of the board and do not require drilling.
The heat-oven method of soldering requires a specially designed oven. The SMD components are
first placed on the board with a solder flux paste spread over all of its terminals. The paste is sticky
enough to keep the components in place until placing the board in the oven. Most reflow ovens
operate in four stages. In the first stage, the temperature of the oven is raised slowly, at a rate of
about 2 degrees Celsius per second to about 200 degrees Celsius. In the next stage, which lasts
for about one to two minutes, the temperature increment rate is significantly lowered. During this
stage, the flux starts to react with the lead and the pad to form bonds. The temperature is further
raised in the next stage to about 220 degrees Celsius to complete the melting and bonding
process. This stage generally takes less than a minute to complete, after which the cooling stage
begins. During cooling, the temperature is rapidly decreased to a little above room temperature,
which helps in quick solidification of the solder flux.

Desoldering with Copper Braid

Soldering: https://images.app.goo.gl/34nGBy8tYVejETuE8
Copper braid is commonly used to desolder electronic components. This technique involves melting
the solder flux and then allowing the copper braid to absorb it. The braid is placed on the solid
solder and gently pressed with a heated soldering iron tip. The tip melts the solder, which is quickly
absorbed by the braid. This is an efficient but slow method of desoldering components since each
soldered joint must be worked on individually.
Desoldering with Solder Sucker

Source: https://www.build-electronic-circuits.com/wp-content/uploads/2013/03/desolder-using-solder-sucker.jpg
Solder sucker is basically a small tube connected to a vacuum pump. Its purpose is to suck the
molten flux off of pads. A heated soldering iron tip is first placed on the solid solder until it melts.
The solder sucker is then placed directly on the molten flux and a button on its side is pushed that
quickly sucks the flux.
Desoldering with Heat Gun

Source: https://images.app.goo.gl/JZjRCphzp7uXhoFg8

Desoldering with a heat gun is generally used to desolder SMD components, though it can also be
employed for through-hole components. In this method, the board is placed in a perfectly flat place
and a heat gun is pointed directly at the components to be desoldered for a few seconds.This
quickly melts the solder and on the pads, loosening the components. They are then immediately
lifted with the help of tweezers. The downside of this method is that it is very difficult to use for
small, individual components since the heat can melt the solder on nearby pads, which can
dislodge components that are not desoldered. Also, the molten flux can flow to nearby traces and
pads, causing electrical shorts. It is therefore very important to keep the board as flat as possible
during this process.

QUIZ 6: SINGLE CHOICE

1. Generally used to desolder SMD components, though it can also be employed for through-
hole components

A.DESOLDERING WITH HEAT GUN
B.DESOLDERING WITH COPPER BRAID
C.DESOLDERING WITH SUCKER

2. A small tube connected to a vacuum pump. Its purpose is to suck the molten flux off of
pads

A.DESOLDERING WITH HEAT GUN
B.DESOLDERING WITH COPPER BRAID
C.DESOLDERING WITH SUCKER

3. Commonly used to desolder electronic components. This technique involves melting the
solder flux.

A.DESOLDERING WITH HEAT GUN

B.DESOLDERING WITH COPPER BRAID
C.DESOLDERING WITH SUCKER

4. Commonly used tool to solder components on PCBs. Generally,heated to a temperature of
about 420 degrees Celsius, which is enough to quickly melt the solder flux.

A.SOLDERING WITH SOLDERING IRON
B.REFLOW SOLDERING
C.DESOLDERING WITH COPPER BRAID

5. Generally used in PCB production environments in which large numbers of SMD
components need to be soldered at the same time.

A.SOLDERING WITH SOLDERING IRON
B.REFLOW SOLDERING
C.DESOLDERING WITH COPPER BRAID

6. It is performed to install a component on a PCB or to remove it from the board.

A.SOLDERING WITH SOLDERING IRON
B.SOLDERING
C.SOLDERING AND DESOLDERING

Lesson 2 Soldering Procedure

Source: https://www.harrisproductsgroup.com/en/Expert-Advice/tech-tips/procedures-for-soldering.aspx

Soldering is a joining process where coalescence is produced by heating below 800°F, using a
non-ferrous filler metal with a melting point below that of the base metal. The metals to be joined
dictate the flux, solder, and heating methods to be used. Base metals are selected for specific
properties such as electrical conductivity, weight, and corrosion resistance.

To achieve a sound soldered joint, the following should be considered:

• Joint design: They should be designed with the requirements of solders and their limitations
in mind.

• Pre-cleaning: The surfaces must be thoroughly cleaned to allow the solder to wet the base
metal.

• Fluxing: A flux must be provided to remove traces of surface film or oxides and to prevent
formation of oxides during the soldering operation.

• Proper fixtures or alignment of parts must be maintained to insure a sound soldered joint.

• Heating of the base metals should be uniform or even on base metals, to insure good
penetration of the filler alloy into the joint. If a noncorrosive flux is used no further cleaning is
necessary. The use of a corrosive flux makes flux residue removal imperative.

Steps in Soldering Process

1.

Source: https://images.app.goo.gl/7NPQ9YDfCmZyhReq6

Melting the Solder

This is the very first step in the entire wave soldering process. It is the basic requirement of the process to
melt the solder. The wave soldering machine has solder contained in a tank. The tank is heated to melt the
solder. Appropriate temperature is reached to meet the right consistency, so that the process of soldering

can be carried out further.

2.

Source: https://images.app.goo.gl/pvPbZJ9C5DidZ2Nu6
Cleaning the Components

This is a very crucial step to be carried out. The components to be soldered are cleaning thoroughly in this
step. If any oxide layers are formed on the components, then they are removed. This is done by the process

called fluxing. There are two main types of fluxing – corrosive (high acidity) and noncorrosive (high acidity).
3.

Source: https://www.cognex.com/en-be/industries/electronics/oem-and-machine-building/pcb-component-placement-guidance
Placement of the PCB
After melting the solder and cleaning the components to be soldered, the printed circuit board is placed on
the melted solder. The board is held with the metal clasps of the machine, which ensure the firm positioning
and placement of the PCB.
4.

.
Source: https://images.app.goo.gl/cRgtpUsabDYBLMPw6

Application of Solder
Now that the PCB is placed properly, molten solder is applied, and is allowed to settle. Sufficient time is

given to this step to allow the solder to settle into the joints completely, and ensure no bumps are formed.
5.

Source: https://www.kitronik.co.uk/blog/clean-maintain-soldering-iron/
Cleaning
This is the final step in the wave soldering process. Any flux residues formed during the process are cleaned
in this step. The circuit board is washed and cleaned with the help of deionized water and solvents.
Source: https://www.harrisproductsgroup.com/en/Expert-Advice/tech-tips/procedures-for-soldering.aspx
https://www.acceleratedassemblies.com/blog/5-important-steps-of-a-wave-soldering-process/
DRAG AND DROP

Topic 6 Handling electronic components
Lesson 1 Proper Handling Electronic Components

Source: https://images.app.goo.gl/tdsboZY1kh43pVa68

Work areas must be kept clean and neat. To prevent contamination of circuit board assemblies,
there must be no eating or smoking in the work area. When not being worked on, sensitive
components and circuit boards must be enclosed in shielded bags or boxes.

Component Handling Precautions

Electronic components such as small diodes and CMOS ICs need careful handling, but beginners
may not know what situations may cause damage, and what precautions to take. You should take
reasonable care in handling all components, but certain components can be damaged by high
voltage static charges. It is easy for static charges to accumulate on your body without evidence of
their presence, because they are generated by friction between insulating materials such as many
plastics, fabrics, and other common materials. For instance, if you walk across a carpet to your
workplace, you can accumulate a static charge of several hundred volts. Voltage is destructive to
electronic devices.

CMOS devices such as the ICs used in the Minimum Theremin kit can be damaged by voltages as
low as 250 volts, so the first precaution is to ensure that you have not accumulated a static charge.
A person handling such devices in the course of their daily work may have a grounded mat on their

benchtop and a grounded wrist strap. However, the occasional kit builder does not have to go to
such extents to ensure that static charges on their body are dissipated. Such charges can be
dissipated by touching the metal casing of grounded equipment at your workplace (e.g., a piece of
test equipment). If you do not have such equipment available, then you can run a wire from the
cover screw of a nearby electrical outlet and connect it through a 1 megohm resistor to a small
metal plate attached to your work surface. This arrangement is illustrated in the figure below.

I

The two CMOS ICs in the Minimum Theremin Kit are supplied in protective carbon-filled foam that
"shunts" static charges to prevent them from flowing between the ICs pins. An antistatic plastic bag,
distinguished by its pink color, is used for the voltage regulator. The correct procedure for handling
these sensitive parts is to:

1. Touch your grounded equipment or grounded plate.

2. Remove the device from its protective foam or bag.

3. Solder the device to the printed circuit board.

To prevent static charges from accumulating on your body, it is best to perform these steps without
leaving your workplace. If you do leave your workplace between steps, touch your grounded
equipment or grounded plate immediately before touching any of the individual parts or the printed
circuit board. Once the assembly is complete, the electrical interconnections on the printed circuit
board provide an increased degree of protection from static electric charges, however, it is still
recommended that you discharge any static charges on your body before you touch the completed
assembly.

Always make sure that a part is inserted in the correct orientation before you solder it in place.

Source: https://harrisoninstruments.com/101/component_handling_precautions.html

Quiz 7 True or False

TOPIC 7 Mount electronic components
Lesson 1 Mount electronic components

Source: https://images.app.goo.gl/YKhxNuyXVPqNoR568
Surface-mount technology (SMT) is a method in which the electrical components are mounted
directly onto the surface of a printed circuit board (PCB). An electrical component mounted in
this manner is referred to as a surface-mount device (SMD).Is Surface Mount Technology
important?
A huge majority of today’s electronics are manufactured with SMT, or surface mount technology.
Devices and products that use SMT have a large number of advantages over traditionally routed
circuits; these devices are known as SMDs, or surface mount devices. These advantages have
ensured that SMT has dominated the PCB world since its conception.

Advantages of SMT
▪ The main advantage for SMT is to allow automated production and soldering. This is
cost and time saving and also allows for a far more consistent circuit. The savings in
manufacturing costs are often passed along to the customer – making it beneficial for
everyone.
▪ Less holes need to be drilled on circuit boards
▪ Costs are lower than through-hole equivalent parts
▪ Either side of a circuit board can have components placed on it
▪ SMT components are far smaller
▪ Higher component density

▪ Better performance under shake and vibration conditions.

Disadvantages of SMT

▪ Large or high-power parts are unsuitable unless through hole construction is used.
▪ Manual repair can be extremely difficult due to the extremely low size of components.
▪ SMT can be unsuitable for components that receive frequent connecting and

disconnecting.

What are SMT devices

Surface mount devices or SMDs are devices that use surface mount technology. The various
components used are designed specifically to be soldered directly to a board rather than wired
between two points. There are three main categories of SMT components.

Passive SMDs
The majority of passive SMDs are resistors or capacitors. The package sizes for these are well
standardised, other components including coils, crystals and others tend to have more specific
requirements.

Integrated circuits
For more information about integrated circuits in general. In relation to SMD specifically, they can
vary extensively depending on the connectivity needed.

Transistors and diodes
Transistors and diodes are often found in a small plastic package. Leads form connections and
touch the board. These packages use three leads.

A brief history of SMT

Surface mount technology became widely used in the 1980s, and popularity has only grown from
there. PCB producers quickly realised that SMT devices were much more efficient to produce than
existing methods. SMT allows for production to be highly mechanised. Previously, PCBs had used
wires to connect up their components. These wires were administered by hand using the through-
hole method. Holes in the surface of the board had wires threaded through them, and these, in turn,
connected the components together. Traditional PCBs needed humans to assist in this
manufacture. SMT removed this cumbersome step from the process. Components were instead
soldered onto pads on the boards instead – hence ‘surface mount’.

SMT catches on

The way that SMT lent itself to mechanisation meant that usage spread quickly throughout the
industry. A whole new set of components were created to accompany this. These are often smaller
than their through-hole counterparts. SMDs were able to have a much higher pin count. In general
SMTs are also much more compact than through-hole circuit boards, allowing for lower
transportation costs. Overall, the devices are simply much more efficient and economical. They are
capable of technological advances that could not have been imaginable using through-hole.

Source: https://images.app.goo.gl/KBD2NFJurrmFEzCq7

Thru Hole Mount

A circuit board packaging technique in which the leads (pins) on discrete components and chips are
inserted through holes in the printed circuit board and soldered from beneath. Until the late 1980s
and prior to surface mount technology, all devices on circuit boards were thru-hole. Although chips
are mostly surface mounted these days, some chips are still thru-hole, and most discrete devices
such as resistors and capacitors are thru-hole.

Thru-hole devices have a strong bond with the board but require an extra drilling step. They also
eliminate the board real estate underneath from being used for other layers. Through-hole
technology almost completely replaced earlier electronics assembly techniques such as point-to-
point construction. From the second generation of computers in the 1950s until surface-mount
technology (SMT) became popular in the late 1980s, every component on a typical PCB was a
through-hole component. PCBs initially had tracks printed on one side only, later both sides, then
multi-layer boards were in use. Through holes became plated-through holes (PTH) in order for
the components to make contact with the required conductive layers. Plated-through holes are no
longer required with SMT boards for making the component connections, but are still us

Sources: https://en.wikipedia.org/wiki/Surface-mount_technology
https://www.pcbtrain.co.uk/blog/what-is-surface-mount-technology-smt
https://www.pcmag.com/encyclopedia/term/thru-hole
https://en.wikipedia.org/wiki/Through-hole_technology

Quiz 8

WEB SCRIPT Electrical and Electronics
Sector: Electronics Products Assembly and Servicing NC II
Qualification: Assemble Electronic Products
Unit of Competency: Assembling Electronic Products
Module Title: LO4: Perform electronic products assembly
Learning Outcomes: Kendrick Jim Tabi
Developer/s:

TITLE
OBJECTIVES
Topic 8

INTRODUCTION

Lesson 1

WEB SCRIPT Electrical and Electronics
Sector: Electronics Products Assembly and Servicing NC II
Qualification: Assemble Electronic Products
Unit of Competency: Assembling Electronic Products
Module Title: LO5: Test and Inspect assembled Electronic Products
Learning Outcomes: John Abrigo Aragones
Developer/s:

TITLE Testing and Inspecting assembled Electronic Products
OBJECTIVES
Topic 8

INTRODUCTION

Lesson 1
Prepared by:
Jomar T. Marfil
EPAS – Trainer, JZGMSAT
Output: LO1: Prepare to Assemble Electronic products