Inductors are all but unheard of in integrated circuits. They can be made by laying down a metal wire in the form of a spiral but it takes up a lot of space and is almost never done. It is possible to wire an amplifier with a capacitor so it acts like an inductor. It is called a gyrator. Gyrators can be used at audio and low radio frequencies.
Regards. Max. K 4 O D S. Email: [EMAIL PROTECTED] Transistor site http://www.funwithtransistors.net Vacuum tube site: http://www.funwithtubes.net Music site: http://www.maxsmusicplace.com To subscribe to the fun with tubes group send an email to, [EMAIL PROTECTED] ----- Original Message ----- From: "Boyce, Ray" <[EMAIL PROTECTED]> To: <[email protected]> Sent: Monday, August 27, 2007 4:47 PM Subject: RE: [BlindHandyMan] What Do You Want Information ON? > Hi > Our world is full of integrated circuits. You find several of them in > computers. For example, most people have probably heard about the > microprocessor. > The microprocessor is an integrated circuit that processes all > information in the computer. It keeps track of what keys are pressed and > if the mouse has > been moved. It counts numbers and runs programs, games and the operating > system. Integrated circuits are also found in almost every modern > electrical device > such as cars, television sets, CD players, cellular phones, etc. But > what is an integrated circuit and what is the history behind it? > > Electric Circuits > > The integrated circuit is nothing more than a very advanced electric > circuit. An electric circuit is made from different electrical > components such as transistors, > resistors, capacitors and diodes, that are connected to each other in > different ways. These components have different behaviors. > > The transistor acts like a switch. It can turn electricity on or off, or > it can amplify current. It is used for example in computers to store > information, > or in stereo amplifiers to make the sound signal stronger. > > The resistor limits the flow of electricity and gives us the possibility > to control the amount of current that is allowed to pass. Resistors are > used, among > other things, to control the volume in television sets or radios. > > The capacitor collects electricity and releases it all in one quick > burst; like for instance in cameras where a tiny battery can provide > enough energy to > fire the flashbulb. > > The diode stops electricity under some conditions and allows it to pass > only when these conditions change. This is used in, for example, > photocells where > a light beam that is broken triggers the diode to stop electricity from > flowing through it. > > These components are like the building blocks in an electrical > construction kit. Depending on how the components are put together when > building the circuit, > everything from a burglar alarm to a computer microprocessor can be > constructed. > > > The Transistor vs. the Vacuum Tube > > The vacuum tube and the transistor. > ENIAC-The first digital computer > Of the components mentioned above, the transistor is the most important > one for the development of modern computers. Before the transistor, > engineers had > to use vacuum tubes. Just as the transistor, the vacuum tube can switch > electricity on or off, or amplify a current. So why was the vacuum tube > replaced > by the transistor? There are several reasons. > > The vacuum tube looks and behaves very much like a light bulb; it > generates a lot of heat and has a tendency to burn out. Also, compared > to the transistor > it is slow, big and bulky. > > When engineers tried to build complex circuits using the vacuum tube, > they quickly became aware of its limitations. The first digital computer > ENIAC, for > example, was a huge monster that weighed over thirty tons, and consumed > 200 kilowatts of electrical power. It had around 18,000 vacuum tubes > that constantly > burned out, making it very unreliable. > > When the transistor was invented in 1947 it was considered a revolution. > Small, fast, reliable and effective, it quickly replaced the vacuum > tube. Freed > from the limitations of the vacuum tube, engineers finally could begin > to realize the electrical constructions of their dreams, or could they? > > > The Tyranny of Numbers > > With the small and effective transistor at their hands, electrical > engineers of the 50s saw the possibilities of constructing far more > advanced circuits > than before. However, as the complexity of the circuits grew, problems > started arising. > > When building a circuit, it is very important that all connections are > intact. If not, the electrical current will be stopped on its way > through the circuit, > making the circuit fail. Before the integrated circuit, assembly workers > had to construct circuits by hand, soldering each component in place and > connecting > them with metal wires. Engineers soon realized that manually assembling > the vast number of tiny components needed in, for example, a computer > would be > impossible, especially without generating a single faulty connection. > > Another problem was the size of the circuits. A complex circuit, like a > computer, was dependent on speed. If the components of the computer were > too large > or the wires interconnecting them too long, the electric signals > couldn't travel fast enough through the circuit, thus making the > computer too slow to > be effective. > > So there was a problem of numbers. Advanced circuits contained so many > components and connections that they were virtually impossible to build. > This problem > was known as the tyranny of numbers. > > > Jack Kilby's Chip - the Monolithic Idea > > In the summer of 1958 Jack Kilby at Texas Instruments found a solution > to this problem. He was newly employed and had been set to work on a > project to build > smaller electrical circuits. However, the path that Texas Instruments > had chosen for its miniaturization project didn't seem to be the right > one to Kilby. > > Because he was newly employed, Kilby had no vacation like the rest of > the staff. Working alone in the lab, he saw an opportunity to find a > solution of his > own to the miniaturization problem. Kilby's idea was to make all the > components and the chip out of the same block (monolith) of > semiconductor material. > When the rest of the workers returned from vacation, Kilby presented his > new idea to his superiors. He was allowed to build a test version of his > circuit. > In September 1958, he had his first integrated circuit ready. It was > tested and it worked perfectly! > > Although the first integrated circuit was pretty crude and had some > problems, the idea was groundbreaking. By making all the parts out of > the same block > of material and adding the metal needed to connect them as a layer on > top of it, there was no more need for individual discrete components. No > more wires > and components had to be assembled manually. The circuits could be made > smaller and the manufacturing process could be automated. > > Jack Kilby is probably most famous for his invention of the integrated > circuit, for which he received the Nobel Prize in Physics in the year > 2000. After > his success with the integrated circuit Kilby stayed with Texas > Instruments and, among other things, he led the team that invented the > hand-held calculator. > > > Robert Noyce > > Robert Noyce came up with his own idea for the integrated circuit. He > did it half a year later than Jack Kilby. Noyce's circuit solved several > practical > problems that Kilby's circuit had, mainly the problem of interconnecting > all the components on the chip. This was done by adding the metal as a > final layer > and then removing some of it so that the wires needed to connect the > components were formed. This made the integrated circuit more suitable > for mass production. > Besides being one of the early pioneers of the integrated circuit, > Robert Noyce also was one of the co-founders of Intel. Intel is one of > the largest manufacturers > of integrated circuits in the world. > > Chip Production Today - in Short > > Stepping. > > Chip production today is based on photolithography. In photolithography > a high energy UV-light is shone through a mask onto a slice of silicon > covered with > a photosensitive film. The mask describes the parts of the chip and the > UV-light will only hit the areas not covered by the mask. When the film > is developed, > the areas hit by light are removed. Now the chip has unprotected and > protected areas forming a pattern that is the first step to the final > components of > the chip. > > Next, the unprotected areas are processed so their electrical properties > change. A new layer of material is added, and the entire process is then > repeated > to build the circuit, layer by layer. When all the components have been > made and the circuit is complete a layer of metal is added. Just as > before, a layer > of photosensitive film is applied and exposed through a mask. However, > this time the mask used describes the layout of the wires connecting all >the parts > of the chip. The film is developed and the unexposed parts are removed. > Next, the metal not protected with film is removed to form the wires. > Finally, > the chip is tested and packaged. > > When making chips today, a process called "stepping" is often used. On a > big wafer of silicon the chips are made one next to the other. The > silicon wafer > is moved in steps under the mask and the UV-light to expose the wafer. > In this way, chip after chip can be made using the same mask each time. > > Below is a more sequential description of the process of making a modern > integrated circuit. But let us first take a look at the special place > where integrated > circuits are produced - the clean room. > > > The Clean Room > > The sizes of the components on chips produced in a modern chip > fabrication plant are extremely small. For a better understanding of how > small they are, > pick a hair from your head and cut it in half. Now look at the cross > section. On this tiny area, hard to see with the bare eye, you can fit > thousands of > modern transistors. > > With sizes this small, the production of a chip demands precision at an > atomic level. Tiny particles like a hair, a speck of dust, a dead skin > cell, bacteria > or even the single particles in tobacco smoke become huge objects that > are big enough to ruin a chip. > > Therefore, chip production takes place in a clean room. This is a > specially designed room, where furniture is built from special materials > that don't give > off particles, and where extremely effective air filters and air > circulation systems change the air completely up to ten times a minute. > > To further prevent contamination, workers wear special suits called > "bunny suits." These protective outfits are made of ultra clean material > and sometimes > have their own air filtering systems. > > Chip Production Today - in Detail > > > Building an integrated circuit like a computer chip is a very complex > process. It is divided into two major parts, front end and back end. In > the front > end, you make the components of the circuit. In the back end, you add > metal to connect the components and then you test and package the chip. > Below is > a simplified description of the steps. > > Front End - Construction of the Components > > 1. > Just as in building a house, you need a construction plan to construct a > chip. The construction plans for the chip are made and tested with a > computer. > > 2. > From the construction plans, masks with the circuit patterns are made. > > 3. > Under precisely monitored conditions, a pure silicon crystal is grown. > Circuit manufacturing demands the use of crystals with an extremely high > grade of > perfection. > > 4. > The silicon is sawed into thin wafers with a diamond saw. The wafers are > then polished in a number of steps until their surface has a perfect > mirror-like > finish. > > 5. > The silicon wafer is covered with a layer of insulating silicon oxide. > > 6. > A covering film of protective material is put on top of the insulating > silicon oxide. This material, a bit like the film in any ordinary > camera, is sensitive > to light. > > > > 7. > UV-light is shone through a mask and onto the chip. On the parts of the > chip that are hit by light, the protective material breaks apart. > > > > 8. > The wafer is developed, rinsed and baked. The development process > removes the parts of the protective material exposed to light. > > > 9. > The wafer is treated with chemicals in a process called "etching." This > removes the unprotected insulating material, creating a pattern of > non-protected > silicon wafer parts surrounded by areas protected by silicon oxide. > > > 10. > The wafer is run through a process that alters the electrical properties > of the unprotected areas of the wafer. This process is called "doping." > Steps 5-10 > are repeated to build the integrated circuit, layer by layer. Other > layers of conducting or isolating layers may also be added to make the > components. > > Back End - Adding the Connecting Wires > > 11. > Finally, when all the components of the chip are ready, metal is added > to connect the components to each other in a process called > metalization. This is > done in a way similar to the making of the components. First a > conducting metal like copper is deposited over the chip. > > 12. > On top of the metal a layer of UV-sensitive photo resist is added. > > > > 13. > Next, a mask that describes the desired layout of the metal wires > connecting the components of the chip is used. UV-light is shone through > this mask. The > light hits the photo resist that isn't protected by the mask. > > > > 14. > In the next step, chemicals are used to remove the photo resist hit by > UV-light. > > > 15. > Another step of etching removes the metal not protected by photo resist. > > > 16. > This leaves a pattern of metal that is the same as the one described by > the mask. Now, the chip has a layer of wires that connect its different > components. > > 17. > Today, most integrated circuits need more than one layer of wires. > Advanced circuits may need up to five different layers of metal to form > all the necessary > connections. In the last picture we have added another layer of metal to > our example. As you can see, a layer of insulating material is put > between the > two metal layers to prevent the wires from connecting in the wrong > places. Of course, to add the second layer we had to go through the same > steps as when > adding the first layer of metal. > > > 18. > When the final layer of connecting metal wires have been added, the > chips on the silicon wafer are tested to see if they perform as > intended. > > > > 19. > The chips on the wafer are separated with a diamond saw to form > individual integrated circuits. > > 20. > Finally, each chip is packed into the protective casing and subjected to > another series of tests. The chip is now finished and ready to be > shipped to manufacturers > of digital devices around the world. > > > > The Evolution of the Integrated Circuit > > J > > The integrated circuit has come a long way since Jack Kilby's first > prototype. His idea founded a new industry and is the key element behind > our computerized > society. Today the most advanced circuits contain several hundred > millions of components on an area no larger than a fingernail. The > transistors on these > chips are around 90 nm, that is 0.00009 millimeters*, which means that > you could fit hundreds of these transistors inside a red blood cell. > > Each year computer chips become more powerful yet cheaper than the year > before. Gordon Moore, one of the early integrated circuit pioneers and > founders > of Intel once said, "If the auto industry advanced as rapidly as the > semiconductor industry, a Rolls Royce would get a half a million miles > per gallon, > and it would be cheaper to throw it away than to park it."** > > > ********************************************************************** > This message and its attachments may contain legally > privileged or confidential information. If you are not the > intended recipient, you must not disclose or use the > information contained in it. If you have received this e-mail > in error, please notify the sender immediately by return > e-mail and delete the e-mail. > > Any content of this message and its attachments which > does not relate to the official business of Eraring Energy > must be taken not to have been sent or endorsed by > Eraring Energy. No warranty is made that the e-mail or > attachment(s) are free from computer virus or other defect. > ********************************************************************** > > > > [Non-text portions of this message have been removed] > > > > To listen to the show archives go to link > http://acbradio.org/handyman.html > or > ftp://ftp.acbradio.org/acbradio-archives/handyman/ > > The Pod Cast address for the Blind Handy Man Show is. > http://www.acbradio.org/news/xml/podcast.php?pgm=saturday > > Visit The Blind Handy Man Files Page To Review Contributions From Various > List Members At The Following address: > http://www.jaws-users.com/handyman/ > > Visit the archives page at the following address > http://www.mail-archive.com/[email protected]/ > > If you would like to join the Blind Computing list, then visit the > following address for more information: > http://jaws-users.com/mailman/listinfo/blind-computing_jaws-users.com > > For a complete list of email commands pertaining to the Blind Handy Man > list just send a blank message to: > [EMAIL PROTECTED] > Yahoo! Groups Links > > > > > > > -- > No virus found in this incoming message. > Checked by AVG Free Edition. > Version: 7.5.484 / Virus Database: 269.12.9/975 - Release Date: 8/26/2007 > 9:34 PM >
