Disassembly Project

Biometric Attendance Machine

Group 2

Team Members

MAKING OF THE

GLASS PLATE

Ameya and Raj

What is glass made of ?

• Sand (mostly SiO₂)
• Soda Ash (Na₂CO₃)
• Limestone (CaCO₃)
• Dolomite ( CaMg(CO₃)₂)
• Salt cake (anhydrous Na₂SO₄)
• Recycled glass

SCORING PROCESS

THERMAL

TEMPERING

TEMPERATURE

TIME

GRAPH

INTEGRATED CIRCUIT

Mitvik

What is an Integrated Circuit?

• An integrated circuit (IC), is a microscopic array of electronic circuits and components that has been diffused or implanted onto the surface of a single crystal, or chip, of semiconducting material such as silicon.
• ICs have demonstrated low cost, high reliability, low power requirements, and high processing speeds compared to the vacuum tubes and transistors which preceded them
• ICs range in complexity from simple logic modules and amplifiers to complete microcomputers containing millions of elements.

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RAW MATERIALS

• Pure silicon (base)
• Silicon dioxide (insulator)
• Phosphorus, Arsenic (N type dopants)
• Boron, Gallium (P type dopants)
• Aluminium (connector)
• Aluminium and Gold (Thin wire leads )
• Ceramics ( mounting package)

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MANUFACTURING PROCESS

The manufacturing process takes place in a tightly controlled environment known as a clean room where the air is filtered to remove foreign particles. Since some IC components are sensitive to certain frequencies of light, even the light sources are filtered. The following are the major processes involved in the manufacturing:

• Preparing the silicon wafer: A thin, round wafer is cut off cylindrical ingot of purified silicon using a precise cutting machine called a wafer slicer
• Masking: The design of each layer is prepared on a computer-aided drafting machine, and the image is made into a mask which will be optically reduced and transferred to the surface of the wafer. It has the images for all of the several hundred integrated circuits to be formed on the wafer

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• Doping-Atomic Diffusion: Method of adding dopants to create a layer of P or N regions is atomic diffusion. As the dopant and gas pass over the wafers, the dopant is deposited on the hot surfaces left exposed by the masking process.
• Making successive layers: The process of masking and etching or doping is repeated for each successive layer until all of the integrated circuit chips are complete.
• Making individual ICs: The thin wafer is like a piece of glass. The hundreds of individual chips are separated by scoring a crosshatch of lines with a fine diamond cutter and then putting the wafer under stress to cause each chip to separate.

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Hazardous Materials and Recycling

The dopants gallium and arsenic, among others, are toxic substances and their storage, use, and disposal must be tightly controlled.

Many ICs and other electronic components are removed from otherwise obsolete equipment, tested, and resold for use in other devices.

The Future

Changes in technology since the device's invention have been rapid, but evolutionary. Many changes have been made in the architecture, or circuit layout, on a chip, but the integrated circuit still remains a silicon-based design.

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Fingerprint Sensor

Content /Parts in sensing

1. LEDs
2. CCD

Optical

Scanning

Capacitive Scanning

In Our Biometric Machine

CCD - Charge Coupled Device

The heart of an optical scanner is a charge coupled device (CCD), the same light sensor system used in digital cameras and camcorders. A CCD is simply an array of light-sensitive diodes called photosites, which generate an electrical signal in response to light photons.

Material : A CCD chip is a metal oxide semiconductor (MOS) device. In the case of the CCD, usually silicon is used as the base material and silicon dioxide is used as the coating.

Manufacturing :

1. The photoactive region of a CCD is, generally, an epitaxial layer of silicon. It is lightly p doped (usually with boron) and is grown upon a substrate material, often p++
2. polysilicon gates are deposited by chemical vapor deposition, patterned with photolithography, and etched in such a way that the separately phased gates lie perpendicular to the channels.
3. Channel stops are thermally grown oxides that serve to isolate the charge packets in one column from those

in another.

Working

The scanning process starts when you place your finger on a glass plate, and a CCD camera takes a picture.

The scanner has its own light source, typically an array of light-emitting diodes, to illuminate the ridges of the finger.

The CCD system actually generates an inverted image of the finger, with darker areas representing more reflected light (the ridges of the finger) and lighter areas representing less reflected light (the valleys between the ridges).

Dynamic changing pattern analysis

FAKE FINGERPRINTS AND SPOOFING

The replicated fingerprint made from materials like clay, gelatin, silicone and rubber is called ‘fake fingerprint’ and authenticating with these fake fingerprints is called ‘spoofing’.

LIVE FINGER DETECTION TECHNOLOGY

Unnaturalness feature analysis

Liveness feature analysis

LCD DISPLAY

Bavish K.

• 128 x 64 pixel backlit LCD
• The basis of LCD technology is the liquid crystal
• In an LCD, an electric current is used to align the Liquid Crystal molecules

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Materials Used

• Glass
• Silicon Dioxide
• Indium Tin oxide
• Polymer (Polyvinyl alcohol, polyamides)
• Liquid Crystal
• The molecules used have to be anisotropic
• Polarizable rod-shaped molecules (like biphenyls, terphenyls, etc.) are common

Manufacturing Process

• First, the two glass substrates must be cut to the proper size, polished, and washed.
• Cutting can be done with a diamond saw or scribe, while polishing involves a process called lapping, in which the glass is held against a rotating wheel that has abrasive particles embedded in it
• After being washed and dried, the substrates are coated with a layer of silicon dioxide

1. Preparing Glass Substrate

Manufacturing Process

• Transparent electrode pattern must be made on the substrates. This is done by completely coating both front and rear glass surfaces with a very thin layer of light-sensitive material indium tin oxide
• A mask with the desired pattern is placed over the glass, and the glass is bombarded with ultraviolet light.
• This light causes the resistive layer it shines on to lose its resistance to etching, allowing the chemicals to eat away both the exposed photoresist and the indium tin oxide below it, thus forming the pattern.

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2. Making electrode pattern

Manufacturing Process

• After the electrode pattern is in place, the substrates must be coated with a polymer. The polymer allows the liquid crystals to align properly with the glass surface
• Polyvinyl alcohol, polyamides, and some silanes can be used

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3. Applying the polymer

Manufacturing Process

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• The liquid crystal material is injected into the appropriate area between the two glass substrates
• The thickness of the LCD cell is usually restricted to 5-25 micrometers.
• To make LCDs more visible, polarizers are added. These are usually made from stretched polyvinyl alcohol films that have iodine in them and that are sandwiched between cellulose acetate layers

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4. Injecting the Liquid Crystal

Mother Board

E. Aakash

Materials Used

Conducting layers are typically made of thin copper foil

Insulating layers dielectric are typically laminated together with epoxy resin prepreg

Board is typically coated with a solder mask that is green in color

PCB CAM/CAD

Manufacturing starts from the fabrication data generated by CAD/CAM software

Performs verification of data, verification for deviations in manufacturing processes and panelization�

Etching unwanted Copper

Mask is created by silk screen printing (big features) or photoengraving(fine features)

Chemical etchents like ammonium persulfate or ferric chloride is used for removing excess copper

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Lamination

Multilayer PCB is made by laminating a stack of materials in a press by applying pressure and heat for a period of time

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Cut through of SDRAM module (multilayer PCB)

Drilling and Masking

Made for external component or interlayer connection

Drilled by bits made of solid coated Tungsten Carbide. Holes may be made conductive, by electroplating or inserting hollow metal eyelets

Final layer of solder mask is applied for protection of final layer of circuit from damage (giving green appearance to the board)

Assembly

After plating and coating drilled PCB, electronic components are assembled, completing the process of motherboard manufacturing

ALUMINIUM ELECTROLYTIC CAPACITOR

Harsh Manani

Materials Required

Anode: high-purity(>99.99%) etched aluminum foil with an aluminum oxide coating Cathode: Aluminium foil(>99%purity) with naturally occuring oxide layer Separator: highly absorbent paper with high purity Encapsulation: Aluminium case Sealing: Rubber plug

Manufacturing Processes

1.Foil slitting

The anode foil, cathode foil, and electrolyte paper are cut to the specified width from the source rolls of the specified length.

2.Lead attachment

Leads for connecting the cathode and anode foil electrodes are attached.

3.Coiling

The electrolytic paper is layered between the anode foil and the electrode foil. A coiled construction separates the electrodes.

4.Filling

This element is filled with the electrolyte.

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5.Assembly

The rubber plug is attached to the filled element. Then, the element is placed in the case.

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6.Sleeve Attachment

The case is slipped into a sleeve printed with the rated voltage, capacitance, and polarity. After which, the sleeve is heat shrunk on to the case.

7.Aging

This capacitor is then connected at rated voltage in a high temperature post-forming device for healing all the dielectric defects resulting from the cutting and winding procedure.

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8.Testing

After aging, a 100% final measurement of capacitance, leakage current, and impedance takes place.

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Manufacturing of�Polycarbonate Casing

Vikram Aditya Sharma

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INJECTION UNIT

In this unit, the polymer is gradually

melted by application of external

heating in the barrel

MOULD

Comprises a cavity and a cooling system. Here, the molten polymer is injected under pressure into the cavity and solidified by controlled cooling

CLAMPING UNIT

maintains pressure inside the mould and keeps it closed during injection and cooling.

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Mould Closing

Injection

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Powdered plastic is fed from a hopper into the barrel, and is carried forward by a rotating screw while being melted by heaters along the length of the barrel. The hot mass keeps accumulating in front of the screw.

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After accumulation, the heated plastic is injected into the mould. As the melt enters the mold, the displaced air escapes through vents in the injection pins and along the parting line.

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Cooling

Plasticising of Resin

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Cooling time is dependent on type of resin used and

thickness of the part. Cooling channels may be present.

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Barrel screw retracts and draws new plastic resin into

the barrel from the material hopper. Heater bands maintain the needed barrel temperature.

The mould opens and the ejector rod moves the ejector pins forward.��The part falls and is captured in a bin located below the mould.�

ELECTRIC CABLES

Kshitiz Singhal

An electrical cable is an assembly of one or more wires running side by side or bundled, mostly covered by an insulation which is used to carry electric current

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Cables Used

Ribbon Cable Single wire

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MANUFACTURING PROCESS

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1. Wire Drawing
2. Insulation
3. Screen
4. Assembly
5. Inner Coverings

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6. Armoring

7. Outer Sheath

8. Quality Control

9. Shipping

Wire-drawing

Reducing the diameter of the copper wire to final diameter to increase its ductility and conductivity

•Copper arrives from the foundry in large coils weighing 5 tonnes. This copper, 8 mm in diameter, is technically known as "wire rod".

•The first stage is called "drawing". The diameter of the wire rod is reduced to 2 mm

•This 2-mm wire is then drawn further to reduce the diameter of the wire to the size needed for each kind of conductor.

•In the last stage of wire-drawing, all the wires undergo a heat treatment called annealing. The aim of this stage is to increase the ductility and conductivity

•The copper wires are grouped together to make conductors. This process is called stranding.

•The next process is insulation.

We place an insulating cover over the conductor to prevent current leakages.

•Insulating material is added by a process of extrusion at high temperature. Several insulating materials may be used: PVC, EPR, XLPE, etc.

•The quality of an insulation material depends on two basic characteristics: its insulation capacity and its heat resistance.

•The material's insulation capacity and its thickness determine the cable's maximum service voltage.

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Screw

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Lalit Kumar Marada

Screws- What are they made of?

The most common materials screws are made of today are composed of low-medium carbon steel wire. Other materials used include brass, stainless steel, nickel alloy or aluminum. Steel can be plated with zinc, nickel, chromium or other plating materials. Other screws have extra finish materials for extra protection and those must be compatible with the raw materials the screw is made from.

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Screw- Manufacturing Process

When first creating a screw, the manufacturers first start with a process called Cold heading. Wire is fed from a mechanical coil through a pre-straightening machine. The wire flows directly into a machine that automatically cuts the wire at its designated point and also cuts the head of the screw blank into its desired shape.

The heading machine uses either an open or closed die that requires one or two punches to create the screw head. The closed die creates an accurate screw blank. On average, the cold heading machine produces 100-500 screw blanks per minute.

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Once the screw is cold headed, the blanks are automatically fed to the thread-cutting dies from a vibrating hopper. The hopper guides the screw blanks down a chute to the dies while making sure the screw are in the correct position to be fed into the machine. The blank is then cut using one of three screw-making techniques:-

• In the reciprocating die, two flat dies are used to cut the screw thread. One die remains still, while the other moves in a reciprocating manner. The blank is rolled between the two.
• When the cylindrical die is used, the screw blank is rolled between the two or three round dies to finish the thread.
• The final stage of thread rolling is the planetary rotary die process. This process holds the screw in place while several cutting machines roll around the blank to create the finished product.

Coin Cell

(CR2032, Maxell 3V)

Syed Muztaba Ali

What is it made of?

The coin type lithium manganese dioxide battery uses manganese dioxide (MnO2) as its positive active material, lithium (Li) as its negative active material, and an organic electrolyte. Polymer separators generally are made from microporous polymer membranes. Collector is made of porous carbon. Electrolyte is Lithium Halide in organic solvent.

Disassembled CR2032 battery From left — negative cup from inner side with layer of lithium (oxidized in air), separator (porous material), cathode (manganese dioxide), metal grid — current collector, metal casing (+) (damaged while opening the cell), on the bottom is plastic insulation ring

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Manufacturing Process

1. Electrode Preparation
2. Cell Assembly
3. Battery Testing

Preparation of Cell Electrode

1. Mill and dry the electrode material.
2. Mix a slurry solution.
3. Tape Casting Coater is used for coating slurry on electrode foil. Dry the coated electrode in a dry oven.
4. Make the electrode uniform, by reducing its thickness

Cell Assembly

1. Cut the electrode and separator and current collector in the desired round shape.
2. The parts are put on top of one another with the electrolyte injected onto the electrode discs.
3. The battery is assembled using crimp cell/crimper, which cases the battery under high pressure.

Cell Testing

1. Cell is tested by connecting it to battery analyzer.
2. It is checked if the CR2032 battery is meeting the required specifications.

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