“pcb” -amit nikam -ashi nagariya. contents what is a pcb? materials of a pcb parts of a pcb ...
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“PCB”-AMIT NIKAM
-ASHI NAGARIYA
CONTENTS What is a PCB? Materials of a PCB Parts of a PCB 1.Components 2. Pads 3. Traces 4. Layers 5. Jumper 6. Solder Mask 7. Silk screen Multilayer PCB Advantages Disadvantages Uses References
What is a PCB?
• Printed Circuit Board• Electronic Board that connects circuit
components• PCB is populated with electronic
components • PCBs are rugged, inexpensive, and can be
highly reliable• Mass manufacturing
MATERIALS OF PCB• Conducting layers are typically made of thin
copper foil.• The board is typically coated with a solder
mask that is green in color. Other colors that are normally available are blue and red.
• Unwanted copper is removed from the substrate after etching leaving only the desired copper traces or pathways
PARTS OF A PCB• Components• Pads• Traces• Layers• Jumper• Solder Mask• Silk screen
COMPONENTS• Components are the actual devices used
in the circuit.• This includes input/output connections.• I/O ports, including power supply
connections, are also important in the PCB design.
PADS• Location that components connect to.• You will solder components to the pads
on the PCB.• Pads will connect to traces.• Pads have an inner diameter and outer
diameter.
TRACES• Traces connect pads together.• Traces are essentially the wiring of the
PCB.• Equivalent to wire for conducting signals• High current traces should be wide• Signal traces usually narrower than
power or ground traces.
LAYERS
• Two layers- TOP and BOTTOM• Most of the components reside on the
top layer• Fewer traces on the top layer• Components are soldered to the pads
on the top layer of PCB • Higher circuit densities• Most soldering done on bottom layer
JUMPERS• Often, many signal wires need to exist in
too small of a space and must overlap.• Running traces on different PCB layers
is an option.• Multilayer PCBs are often expensive.• Solution: use jumpers
SOLDER MASK• Protect copper traces on outer layers from
corrosion• Areas that shouldn't be soldered may be
covered with polymer resist solder mask coating
• Designed to keep solder only in certain areas• Prevents solder form binding between
conductors and thereby creating short circuits
SILK SCREEN• Printing on the solder mask to designate
component locations• Readable information about component
part numbers and placement.• Helpful in assembling, testing and
servicing the circuit board
MULTILAYER PCBS• More then a top and bottom layer.• Typically there will be a power plane,
ground plane, top layer, and bottom layer.
• Sometimes signal layers are added as needed.
ADVANTAGES• Small• Compact• Contained in a convenient, rugged board• The circuit board fabrication cost (pcb cost) is lower with mass
quantity production.• Electronic circuit characteristics are maintained with a proper circuit
board design. • Component wiring and assembly can be mechanized in a circuit
board manufacturing facility. • PCB’s offer uniformity of electrical characteristics from assembly to
assembly. • The location of electronic parts is fixed and so it simplifies
components identification and maintenance of equipment. • Inspection time is reduced because printed circuitry eliminates the
probability of error. • Chances of wrongly wiring or short-circuited wiring are minimized.
DISADVANTAGES• Re designing is required for the new type of
circuit operation. • Very hard to get repaired if it gets damaged.• We can not update it , once printed. • Etching of this PCB generates chemicals
which are the harmful for the environment.....
USESIndustrial PCB Manufacturing• Some examples of PCBs that Tabtronics
has manufactured for industrial use include:
• Controls for ultrasonic technologies• Flex circuits with piezoelectric transducers• Field controls for water treatment systems• Process thickness measurement control
Medical PCB Manufacturing• Some examples of PCBs that Tabtronics has
manufactured for medical use include:• Dosimeter product assembly• 2-axis body movement tracking device used by
doctors and researchers• Eye measurement product with
remote transmitter and receiver• Hospital inventory control devices
REFERENCES
• www.pcbexpress.com• A Practical Guide to high-speed printed
circuit board layout
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