Saturday, 30 September 2017

Soldering Guide

What is solder?

Solder is an alloy (mixture) of tin and lead, typically 60% tin and 40% lead. It melts at a temperature of about 200°C. Coating a surface with solder is called 'tinning' because of the tin content of solder. Lead is poisonous and you should always wash your hands after using solder. Solder for electronics use contains tiny cores of flux, like the wires inside a mains flex. The flux is corrosive, like an acid, and it cleans the metal surfaces as the solder melts. This is why you must melt the solder actually on the joint, not on the iron tip. Without flux most joints would fail because metals quickly oxidise and the solder itself will not flow properly onto a dirty, oxidised, metal surface.
The best size of solder for electronics is 22swg (swg = standard wire gauge).


How to Solder?

First a few safety precautions:

  • Never touch the element or tip of the soldering iron.
    They are very hot (about 400°C) and will give you a nasty burn.
  • Take great care to avoid touching the mains flex with the tip of the iron.
    The iron should have a heatproof flex for extra protection. An ordinary plastic flex will melt immediately if touched by a hot iron and there is a serious risk of burns and electric shock.
  • Always return the soldering iron to its stand when not in use.
    Never put it down on your workbench, even for a moment!
  • Work in a well-ventilated area.
    The smoke formed as you melt solder is mostly from the flux and quite irritating. Avoid breathing it by keeping you head to the side of, not above, your work.
  • Wash your hands after using solder.
    Solder contains lead which is a poisonous metal.

Preparing the soldering iron:

  • Place the soldering iron in its stand and plug in.
    The iron will take a few minutes to reach its operating temperature of about 400°C.
  • Dampen the sponge in the stand.
    The best way to do this is to lift it out the stand and hold it under a cold tap for a moment, then squeeze to remove excess water. It should be damp, not dripping wet.
  • Wait a few minutes for the soldering iron to warm up.
    You can check if it is ready by trying to melt a little solder on the tip.
  • Wipe the tip of the iron on the damp sponge.
    This will clean the tip.
  • Melt a little solder on the tip of the iron.
    This is called 'tinning' and it will help the heat to flow from the iron's tip to the joint. It only needs to be done when you plug in the iron, and occasionally while soldering if you need to wipe the tip clean on the sponge.

You are now ready to start soldering:

  • Hold the soldering iron like a pen, near the base of the handle.
    Imagine you are going to write your name! Remember to never touch the hot element or tip.
  • Touch the soldering iron onto the joint to be made.
    Make sure it touches both the component lead and the track. Hold the tip there for a few seconds and...
  • Feed a little solder onto the joint.
    It should flow smoothly onto the lead and track to form a volcano shape as shown in the diagram. Apply the solder to the joint, not the iron.
  • Remove the solder, then the iron, while keeping the joint still.
    Allow the joint a few seconds to cool before you move the circuit board.
  • Inspect the joint closely.
    It should look shiny and have a 'volcano' shape. If not, you will need to reheat it and feed in a little more solder. This time ensure that both the lead and track are heated fully before applying solder.

Using a heat sink

Some components, such as transistors, can be damaged by heat when soldering so if you are not an expert it is wise to use a heat sink clipped to the lead between the joint and the component body. You can buy a special tool, but a standard crocodile clip works just as well and is cheaper.

Soldering Advice for Components


It is very tempting to start soldering components onto the circuit board straight away, but please take time to identify all the parts first. You are much less likely to make a mistake if you do this!
  1. Stick all the components onto a sheet of paper using sticky tape.
  2. Identify each component and write its name or value beside it.
  3. Add the code (R1, R2, C1 etc.) if necessary.
    Many projects from books and magazines label the components with codes (R1, R2, C1, D1 etc.) and you should use the project's parts list to find these codes if they are given.
  4. Resistor values can be found using the resistor colour code which is explained on our Resistors page. You can print out and make your own Resistor Colour Code Calculator to help you.
  5. Capacitor values can be difficult to find because there are many types with different labelling systems! The various systems are explained on our Capacitors page.
Some components require special care when soldering. Many must be placed the correct way round and a few are easily damaged by the heat from soldering. Appropriate warnings are given in the table below, together with other advice which may be useful when soldering. For more detail on specific components please see the Components page or click on the component name in the table.
For most projects it is best to put the components onto the board in the order given below:



Reminders and Warnings

IC Holders
(DIL sockets)
   IC holder
Connect the correct way round by making sure the notch is at the correct end.
Do NOT put the ICs (chips) in yet.

Resistors    resistor
No special precautions are needed with resistors.

Small value capacitors
(usually less than 1µF)
 small value capacitors
These may be connected either way round.
Take care with polystyrene capacitors because they are easily damaged by heat.

Electrolytic capacitors
(1µF and greater)
electrolytic capacitors

Connect the correct way round. They will be marked with a + or - near one lead.

Connect the correct way round.
Take care with germanium diodes (e.g. OA91) because they are easily damaged by heat.

Connect the correct way round.
The diagram may be labelled a or + for anode and k or - for cathode; yes, it really is k, not c, for cathode! The cathode is the short lead and there may be a slight flat on the body of round LEDs.

Connect the correct way round.
Transistors have 3 'legs' (leads) so extra care is needed to ensure the connections are correct.
Easily damaged by heat.

Wire Links between points on the circuit board.     single core wire

single core wire
Use single core wire, this is one solid wire which is plastic-coated.
If there is no danger of touching other parts you can use tinned copper wire, this has no plastic coating and looks just like solder but it is stiffer.

Battery clips, buzzers and other parts with their own wires   Connect the correct way round.
10 Wires to parts off the circuit board, including switches, relays, variable resistors and loudspeakers.    stranded wire

stranded wire
You should use stranded wire which is flexible and plastic-coated.
Do not use single core wire because this will break when it is repeatedly flexed.
11 ICs (chips)        555 timer IC
Connect the correct way round.
Many ICs are static sensitive.
Leave ICs in their antistatic packaging until you need them, then earth your hands by touching a metal water pipe or window frame before touching the ICs.

Carefully insert ICs in their holders: make sure all the pins are lined up with the socket then push down firmly with your thumb.




At some stage you will probably need to desolder a joint to remove or re-position a wire or component. There are two ways to remove the solder: 

1.  With a desoldering pump (solder sucker)
  • Set the pump by pushing the spring-loaded plunger down until it locks.
  • Apply both the pump nozzle and the tip of your soldering iron to the joint.
  • Wait a second or two for the solder to melt.
  • Then press the button on the pump to release the plunger and suck the molten solder into the tool.
  • Repeat if necessary to remove as much solder as possible.
  • The pump will need emptying occasionally by unscrewing the nozzle.

2.  With solder remover wick (copper braid)
  • Apply both the end of the wick and the tip of your soldering iron to the joint.
  • As the solder melts most of it will flow onto the wick, away from the joint.
  • Remove the wick first, then the soldering iron.
  • Cut off and discard the end of the wick coated with solder.

After removing most of the solder from the joint(s) you may be able to remove the wire or component lead straight away (allow a few seconds for it to cool). If the joint will not come apart easily apply your soldering iron to melt the remaining traces of solder at the same time as pulling the joint apart, taking care to avoid burning yourself. 

Monday, 3 April 2017

FIRST Place in "Do-it-yourself" State level project competition, Bagalkote

Sanathraj and team has secured FIRST place in "Do-it-yourself" a state level project competition held at Government Polytechnic, Bagalkote.

Second place @ CONVERGE 2017 , VCET Puttur

Sanathraj and his team secured second place in the event Converge 2017 : Project competition organised by Vivekananda College of Engineering and Technology, Puttur on 1st April, 2017.

Monday, 24 August 2015

E-Club Report 2014-15

Click Here   E-club report 2014-15 

E-club office bearers for the year 2015-16

President                : Abhishek (Final Year)
Vise President       : Videsh (Final Year)
Secretary                : Prashanth Krishna (Final Year)
Joint Secretory     : Suraksha (Final Year)
Treasurer               : Sanathraj (2nd Year)

Monday, 5 January 2015

VLSI Industry Offers Mostly Verification Based Jobs

Today, VLSI devices are found everywhere around us. We find advanced VLSI chips in our cars, cell phones, household appliances, cameras, medical devices and many other places. This rapidly evolving sector offers exciting opportunities for those with strong fundamentals in electronic circuit design and hardware description languages, interest in VLSI design and verification and, more importantly, the skill to put know-how of VLSI concepts to practice.

Abhishek A. Mutha

With the advances being made in technologies like process geometries, feature and product innovations on a daily basis, there is a constant need to design, develop and re-engineer integrated circuits (ICs). Since products like mobile phones are being released with new features in increasingly shorter cycles, there is a healthy demand for qualified very large scale integration (VLSI) engineers to work on these products. Therefore there is good scope for a career in the VLSI industry.

The VLSI field offers exciting growth opportunities for engineers who are strong in electronic design fundamentals, have an interest in VLSI design and verification and know how to apply VLSI concepts to practice. Harish Mysore, director, India operations, Global IEEE Institute for Engineers Private Limited, informs, “In the VLSI chip design and verification alone, 20,000 to 30,000 engineers are currently employed with over 200,000 engineers working in the broader semiconductor industry, including embedded systems development and board-level hardware design.”

According to Vivek Madhukar, COO,, VLSI professionals are always in high demand in the fast-changing chip designing industry. There are over 150 companies catering to this industry, including big names like Texas Instruments, Infineon, Freescale Semiconductor, Cadence, HCL, Intel, Lucent, Motorola, Philips Semiconductor, Qualcomm, Sasken, Conexant, Wipro and TCS, to name a few. He says, “A career in one of these companies is highly sought after and developing VLSI skills is a good way to make this dream a reality.”

It is not easy to get into design

On the flip side, scope for a career in the design side of VLSI industry is currently somewhat limited as compared to other areas, feels Subhajit Sen, associate professor, International Institute of Information Technology, Bangalore, for three particular reasons. One, VLSI or chip design requires a deeper level of knowledge and skills than other electronics related fields. Two, VLSI chip design is expensive and requires access to high- cost, specialised electronic design automation (EDA) tools. Last, VLSI fabrication/prototyping is expensive and there is no commercial VLSI semiconductor manufacturing facility (foundry) in India.K. Srinivasa Raju, CEO, Unistring Tech Solutions Pvt Ltd, informs that there are very few openings for jobs in analogue designing in the VLSI industry. He says, “The expectations in terms of the know-how of analogue complementary metal oxide semiconductor (CMOS) designs/issues are very high, which makes it difficult to get into analogue based VLSI companies. Most of the companies prefer to take M.Techs from only reputed institutes such as NITs/IITs.”However, Sen believes, as India expands its electronics system design and manufacturing (ESDM) capabilities, the number of job opportunities is expected to grow in the VLSI design area.

Mostly verification based jobs in India

Jobs in this industry are broadly distributed in four areas: FPGA based embedded system design, embedded based small FPGA application development, application specific integrated circuits (ASIC) based designs and VLSI verification for FPGAs/ASICs/embedded based designs.

“Most of the jobs in the VLSI industry in India are verification based, particularly for ASIC designs,” informs Raju. To get into such companies, one must be good in SystemVerilog and unified verification methodology (UVM) or open verification methodology (OVM).” He adds, “Most of these verification based companies prefer M.Tech graduates specialised in VLSI design.”

Good opportunities for fresh graduates

There are many career opportunities in the VLSI industry today, especially at the entry-level roles targeted at fresh engineering graduates. “One needs to understand that VLSI, as seen from textbooks, is not just limited to that. Skills such as digital domain and VHDL/Verilog HDL languages can be acquired that are used in FPGA based embedded system industry and also in ASIC companies,” says Raju.Excellent fundamentals in digital electronics, topped with knowledge in either VHDL or Verilog HDL, can easily get an engineer a job in FPGA based companies. Especially for an M.Tech graduate in VLSI, at entry level it is highly possible to get an opportunity to work at the design level in the VLSI industry.
Embedded system design companies that develop FPGA based embedded applications also have openings for fresh graduates. Raju notes, “At the entry level, as fresh undergraduates (B.Tech/B.E.), it is comparatively easier to get into FPGA based embedded system companies than ASIC-VHDL/Verilog HDL based companies.”

This field offers fresh engineering graduates opportunities in several stages of the VLSI chip design process too. “The biggest opportunities continue to be in the front-end register transfer level (RTL) design and verification with growing opportunities in logic synthesis and timing analysis, design for testability, physical design and verification, analogue and mixed signal CMOS IC design, CAD tools development, and hardware verification and validation,” according to Mysore.Fresh graduates also have opportunities in field application engineering, technical support, and marketing and sales.Although VLSI companies typically hire at M.Tech levels for VLSI design positions, candidates with good fundamentals in electronics, electrical or computer science engineering can find positions in areas such as testing and debugging of VLSI chips, informs Sen. He says, “Embedded software, which involves writing code for microcontrollers/processors embedded within VLSI chips, is also an active area of recruitment.”“At our company, we recruit fresher graduates for working in the VLSI domain, provided they are good at the fundamentals of digital logic design (also referred to as digital electronics/switching theory and logic design), digital system design and have done their project implementation in either VHDL/Verilog HDL. We also give internships to M.Tech (in VLSI) students for their second year project work. For internships, we conduct written exams, technical and HR interviews,” shares Raju. He adds, “Currently, our team comprises more than ten engineers working in the field of VLSI. We are planning to recruit ten more for this year. Our recruitment procedure is always in internship mode.”

Pay package and demand areas

“During internship, we pay a stipend of anywhere between ` 4000 and ` 8000 per month, depending on the performance in the internship recruitment procedure. After completion of the internship/project-work, we offer the candidate a job in our company. The salary emolument is typically around Rs 144,000 to Rs 300,000 annually, depending on individual capabilities in technology,” informs Raju. Although, he maintains, MNCs pay double the amount of what they offer at Unistring.

As a skill, chip designers form the cornerstone for electrical and computer engineering domains, and graduates from good institutes can command handsome starting salaries. As per figures provided by, 55 per cent of the engineers (basically feeshers) working in the VLSI domain are paid anywhere between Rs 120,000 and Rs 300,000 per annum. Twenty three per cent engineers draw anywhere between Rs 400,000 and Rs 700,000 per annum and 13 per cent of the (senior) engineers in this industry are paid nearly Rs 1 million and above.

“The silicon valley of India, Bengaluru, accounts for a majority of the jobs, as most companies have their core technology centres based there, with Hyderabad, Delhi, Chennai and Pune accounting for other opportunities in the VLSI sector,” informs Madhukar.

In the near future

The VLSI industry is expected to grow rapidly in the next few years due to further reduction in geometry, reduced power requirements and very large-scale application-specific integrated circuits. As a result, continuous investments will be made by integrated device manufacturers in the semiconductor industry, in addition to the various steps taken by the Indian government to boost indigenous production of electronics in India to address rapid growth in the local demand for electronics. “Further, as a result of the increasing use of electronics in telecom, healthcare, automotive, industrial and office automation, and consumer goods, the need for advanced chip design and verification engineers in the semiconductor industry will further increase,” notes Mysore.