A PRESENTATION ON IN-PLANT TRAINING

SIEMENS LTD, VERNA GOABy

Aniket Pawar

AT

CONTENTS

ABOUT THE COMPANY

METHODOLOGY

PRODUCTION DEPARTMENT

WAREHOUSE AND LOGISTICS

RESEARCH AND DEVELOPMENT CENTER

ABOUT THE COMPANY

Siemens Energy and Automation Verna, Goa is a Greenfield factory with an investment of around Rs. 200 crores.

This factory produces a range of products for power distribution of industries, power plants, infrastructure and cities.

The products include medium voltage gas-insulated switchgears of up to 36k, numerical protection relays, tele-control devices for smart grids.

The factory has its own in-house Research and Development unit.

ABOUT THE COMPANY(CONT.)

This factory is built as green factories with features such as ground water recharging, rain water harvesting, water conservation through low flow fixtures, energy conservation through energy efficient lighting & HVAC, use of solar technology for street lighting and water efficient landscaping.

The Energy Automation factory is the first such factory outside Europe and third in the Siemens World, after Germany and United Kingdom.

METHODOLOGYR & D

DEPARTMENT MANAGEMENT

PRODUCTION DEPARTMENT

SMT LINE AOI & MANUAL INSPECTION

THT MOUNTING & WAVE SOLDERING

INSPECTION & TESTING

DEBUG & REWORK

Packing & LabellingDEVICE ASSEMBLY

ELECTROMECHANICAL ASSEMBLY 1

ELECTROMECHANICAL ASSEMBLY 2

PRODUCTION DEPARTMENT

•SMT PRODUCTION LINE

•AOI (AUTOMATIC OPTICAL INSPECTION)

• THT PRODUCTION LINE

• FINAL MOUNTING and Testing

•STENCIL CLEANING

•DEVICE ASSEMBLY

•Packing - Packing Material

SMT PRODUCTION LINE

PCBs

PCBs

PRINTER PLACEMENTSTAGE 1

PLACEMENTSTAGE 2

PLACEMENTSTAGE 2REFLOW SOLDERING

LOADER

UNLOADER

SMT PLACEMENT EQUIPMENT

SMT component placement systems, commonly called pick-and-place machines or P&Ps, are robotic machines which are used to place surface-mount devices (SMDs) onto a printed circuit board.

They are used for high speed, high precision placing of broad range of electronic components, like capacitors , resistors , integrated circuits onto the PCBs which are in turn used in computers.

COMPONENT FEEDERS

•Surface mount components are placed along the front and back faces of the machine.

• Most components are supplied on paper or plastic tape, in tape reels that are loaded onto feeders mounted to the machine.

•Larger integrated circuits are sometimes supplied arranged in trays which are stacked in a compartment.

REFLOW SOLDERING

There are usually four stages, called "zones", each having a distinct thermal profile:

•PREHEAT•THERMAL SOAK•REFLOW•COOLING

REFLOW SOLDERING

•Preheat: The preheat zone is often the lengthiest of the zones. Here the solvent in the paste begins to evaporate.

•Thermal soak: thermal soak, is typically a 60 to 120 second exposure for removal of solder paste volatiles and activation of the fluxes, where the flux components begin oxide reduction on component leads and pads.

REFLOW SOLDERING(CONT.)

•Reflow: It is the part of the process where the maximum temperature is reached. Temperature limit is determined by the component on the assembly with the lowest tolerance for high temperatures.

•Cooling: The last zone is a cooling zone to gradually cool the processed board and solidify the solder joints. Proper cooling inhibits excess inter-metallic formation or thermal shock to the components.

AOI (AUTOMATIC OPTICAL INSPECTION)

A Small Scale AOI Machine

Types: Stand-alone and inline AOI systems, Closed- and open-top AOI systems, AOI and combined AOI/AXI systems.

LOADER AOI MACHINE UNLOADER

AOI (AUTOMATIC OPTICAL INSPECTION)

A machine vision or an AOI system can acquire millions of data points (pixels) in a fraction of a second.

These data points are used for visual inspection and precision measurement. AOI visually scans the surface of the PCB.

The board is lit by several light sources and observed by a scanner or by a number of high definition cameras.

This enables the monitoring of all areas of the board, even those hidden in one direction by other components.

THT PRODUCTION LINE

PCBS

PCBs for Testing

MOUNTING CELL

MANUAL INSPECTION

WAVE SOLDERING

MANUAL INSPECTION

FINAL MOUNTING

THT PRODUCTION LINE

HOLE

The mounting scheme used for electronic components that involves the use of leads on the components that are inserted into holes drilled in printed circuit boards and soldered to pads on the opposite side either by manual assembly (hand placement) or by the use of automated insertion mount machines

WAVE SOLDERING

Wave soldering is used for both through-hole printed circuit assemblies, and surface mount.

Different Zones:

FluxingPreheating

SolderingCooling

WAVE SOLDERING(CONT.)

PROCESS:The basic equipment used during the process is a conveyor

that moves the PCB through the different zones, a pan of solder used in the soldering process.

A pump that produces the actual wave, the sprayer for the flux and the preheating pad.

WAVE SOLDERING(CONT.)

FLUXING:The primary objective is to clean the components that are

to be soldered, principally any oxide layers that may have formed.There are two types of flux, corrosive and noncorrosive.

Noncorrosive flux requires pre-cleaning and is used when low acidity is required. Corrosive flux is quick and requires little pre-cleaning, but has a higher acidity.

WAVE SOLDERING(CONT.)

PREHEATING:The preheating zone consists of convection heaters which

blow hot air onto the PCB to increase its temperature. For thicker or densely populated PCBs, an upper pre-heater might be used.

Preheating is necessary to activate the flux, and to remove any flux carrier solvents. Preheating is also necessary to prevent thermal shock.

WAVE SOLDERING(CONT.)

SOLDERING:The tank of molten solder has a pattern of standing waves

on its surface. When the PCB is moved over this tank, the solder waves

contact the bottom of the board, and stick to the solder pads and component leads via surface tension.

WAVE SOLDERING(CONT.)

SOLDERING (CONT.):This process is sometimes performed in an inert nitrogen

(N2) atmosphere to increase the quality of the joints. The presence of N 2 also reduces oxidization known as solder dross.

Solder dross, its reduction and elimination, is a growing industry concern as lead soldering is being replaced by lead-free alternatives at significantly higher cost.

WAVE SOLDERING(CONT.)

CLEANING:Some types of flux, called "no- clean" fluxes, do not

require cleaning; their residues are benign after the soldering process.

Others, however, require a cleaning stage, in which the PCB is washed with solvents and/or de-ionized water to remove flux residue.

FINISH AND QUALITY:Quality depends on proper temperatures when heating

and on properly treated surfaces.

FINAL MOUNTING

This includes various processes depending on different PCB models. This include

Hot melt adhesiveSolderingDisplay mounting

FINAL MOUNTING(CONT.)

HOT MELT ADHESIVE (HMA):

Also known as hot glue, is a form of thermoplastic adhesive that is commonly supplied in solid cylindrical sticks of various diameters, designed to be melted in an electric hot glue gun.

The gun uses a heating element to melt the plastic glue, which may be pushed through the gun by a mechanical trigger mechanism, or directly by the user.

The glue is tacky when hot, and solidifies in a few seconds to one minute.

FINAL MOUNTING(CONT.)

Hot melt adhesive (HMA)

FINAL MOUNTING(CONT.)

SOLDERING:

Filler materials are available in many different alloys for differing applications.

In electronics assembly, the eutectic alloy of 63% tin and 37% lead (or 60/40, which is almost identical in melting point) has been the alloy of choice.

There are three forms of soldering soft soldering, which originally used a tin-lead alloy as the filler metal, silver soldering, which uses an alloy containing silver, brazing which uses a brass alloy for the filler.

TESTING

Additional hardware includes:Cameras to test for presence and correct orientation of

components Photo detectors to test for LED color and intensity External timer counter

BED OF NAILS TESTERA bed of nails tester is a

traditional electronic test fixture which has numerous pins inserted into holes which are aligned using tooling pins to make contact with test points.

TESTING(CONT.)

Flying probe testing uses electro-mechanically controlled probes to access components on printed circuit assemblies (PCAs). Commonly used for test of analog components, analog signature analysis and short/open circuits.

They provide an alternative to the bed-of-nails technique for contacting the components on printed circuit boards.

FLYING PROBE TESTERFlying probe test systems are

often used for only testing basic production, prototypes, and boards that present accessibility problems.

STENCIL CLEANING

PROCESSES

Ultrasonic Stencil Cleaning is one of the preferred methods for removing trace levels of solder paste from stencil openings.

Spray-In-Air C8882 WASH / C8882 RINSE Cybersolv® C8882 is a solvent-based stencil cleaning fluid

specifically designed to clean wet solder paste, SMT adhesive and flux residue from stencils (conventional and plastic pump), mis-printed PCBs, wave soldering pallets and tools, fixtures and squeegees.

DEVICE ASSEMBLY

Outer AssemblyContact leads are placed and connected to the former with

the help of screws.

Housing Box AssemblyIt is associated with the mounting of whole structure in a

metallic box.

RivetingA rivet is a permanent mechanical fastener. Before being

installed, a rivet consists of a smooth cylindrical shaft with a head on one end. The end opposite the head is called the buck-tail. On installation the rivet is placed in a punched or drilled hole.

DEVICE ASSEMBLY(CONT.)

Front Panel AssemblyHere, the front panel assembly for the various devices is

done. These include PCBs with control buttons, LCD screens and status LEDs, etc.

 PCBA(PCB Assembly):After the printed circuit board is completed, electronic

components must be attached to form a functional printed circuit assembly or PCA.

WiringWires are attached from PCB components to input and

output ports and power supply points.

DEVICE ASSEMBLY(CONT.)

Inner Block AssemblyFinal and one of the last inner blocks are assembled and a

manual inspection is made.

TestingTesting is commonly done to maintain quality control in

this stage of PCB manufacturing. While the power is off, analog signature analysis, power-off

testing is done. While the power is on, in-circuit tests, where physical

measurements (for example, voltage) can be done. While the power is on, functional test, just checking if the

PCB does what it had been designed to do.

PACKING

BAGS & PACKETSPaper bagsClear plastic bags Zipper bagsGreaseproof bags

PROTECTIVE PACKAGINGAir bubble wrap Corrugated Kraft (SFK)

PACKING(CONT.)

CORRUGATED CARTONSSingle wallDouble Wall

SELF ADHESIVE TAPESStationery tapeDouble sided film tape Double sided foam tapeMasking tapePoly-prop TapeColored PVC Tape

THANK YOU