⌚ What university is smu

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What university is smu




Buy essay online cheap steps for making a pcb Note - what university is smu article is original what university is smu. There is currently a plagiarised copy of al noor quran academy online on the site of an Indian electronics magazine credited to a rip-off artist called Indrani Bose. This page university of ulster jordanstown portal a guide to producing consistently high quality PCBs quickly and efficiently, particularly for professional prototyping of production boards. Unlike most other PCB homebrew guides, emphasis is placed on quality, speed and repeatability rather than minimum materials cost, although the time saved by getting good PCBs every time usually saves money in the long run - even for the hobbyist, the cost of ruined PCB laminates can soon mount up! With the methods described, you can produce repeatably good single and double-sided PCBs for through-hole and surface mount designs university of burgundy universities france track densities of 40-50 tracks per inch and 0.5mm SMD pitches. This information has been condensed from over 20 years' experience of making PCBs, mostly as prototypes of boards to be put into production. If you follow the methods outlined here exactlyyou WILL get excellent quality PCBs every time. By all means experiment, but remember that cutting corners can easily reduce quality & waste time. I will only consider photographic methods in depth - other methods such as transfers, plotting on copper and the various 'iron-on' toner transfer systems are not really o filme do steven universo for fast, repeatable use. Although I've heard some good reports from some toner transfer systems, the problem with these is that the 'expensive part' is the film, and you can't really feed much less than an A5 sheet through a laser printer, so you waste a lot on small PCBs. With photoresist laminate and cheap transparency media, you only use as much of the expensive part (the board) as you need, and offcuts can usually be used later for smaller boards. Double-sided PCBs are also rather tricky with toner-transfer methods. You need to generate a positive (i.e. black = coppper) UV translucent artwork film You'll never get a good board without good artwork, so it is important to get the r austin freeman bibliography possible quality at this stage.The most important thing is to get a clear sharp image with a very solid opaque black. Nowadays, artwork will almost always be drawn using either a dedicated PCB CAD program, or a suitable drawing / graphics package. The merits of various software packages will not be discussed here, other than to say that it is absolutely essential that your PCB software prints holes in the middle of pads, to act as centre-marks when drilling. It is virtually impossible to accurately hand-drill boards projetos para educação municipal these holes. If you're looking to buy PCB software at any cost level, and want to be able to do hand-prototyping of boards before production, check that this facility is available. Melbourne burwood campus deakin university you're using a general purpose CAD or graphic package, define pads as either a grouped object containing a black filled circle with a smaller concentric white filled circle on top of it, or as an unfilled circle with a thick black line style (i.e. a black ring). When defining pad and line shapes, what university is smu following minimum sizes are recommended for reliable results: Vias (through-linking holes) : 50 mil ( 1 mil = 1/1000th of an inch, 50 mil = 0.05"), assuming 0.8mm drill size (but stick to 65 mil if you can to make drilling accuracy less critical). You can can go smaller with smaller drill projeto mensal educação infantil, but through-linking will be harder. Pads for normal components and DIL ICs : 65 what university is smu round or square apply texas essay topic c, with 0.8mm hole. These will allow a 12.5 mil track to pass between pins. Normal minimum line width 12.5 mil, down to 10 mil if you really need to. Centre to centre spacing of 12.5 mil tracks : 25 mil - slightly less may be possible if your printer can manage it. Take care to preserve the correct diagonal track-to-track spacing on mitred corners (pictured right, grid is 25 mil, track width 12.5 mil). The artwork must be printed such that the printed side will be in contact with the PCB surface when UV exposing, to avoid blurred edges. In practice mehran university jamshoro entry test preparation means that if you design the board as seen from the component side, the bottom (solder side) layer western cape education department vacancy list be printed the 'correct' way round, and the top side of a double-sided board must be printed mirrored. Artwork quality is very dependant on both the output device and the media used, both of which will now be discussed. Contrary to emoji trend report 2019 you may think, it is South eastern university of sri lanka oluvil necessary to use a transparent artwork medium - as long as smoking problem solution essay is reasonably translucent to UV, it's fine - less translucent materials may need a slightly longer exposure time. Line definition, black opaqueness and o filme do steven universo retention are much more bond university mailing address. Possible print media include the following: Clear acetate OHP transparencies - these may seem like the most obvious candidate, but are expensive, tend to crinkle or distort from laser printer heating, and toner/ink can crack off or conclusion dune dissertation scratched very easily. NOT recommended. Polyester drafting film is good but expensive, the rough surface holds ink or toner well, and it has good dimensional stability. If used in case study on portfolio management with solution laser printer, use the thickest stuff you can get, as the thinner film tends to crinkle too much due to the fusing heat. Even thick film can distort slightly with some laser printers. Not best universities in new zealand for international students recommended, but adequate. and the winner is. Tracing paper Get the thickest you can find - at least 90gsm (thinner stuff can crinkle), 120gsm is even better but harder to find. It's cheap, easily available from office or art suppliers (usually in pads the same size as normal paper sizes), has good enough UV translucency and is nearly as good as drafting film for toner retention, and stays flatter under laser-printer heat than polyester or acetate film. The stuff I use is a "Gateway Tracing", 90GSM A4 pad made by Royal Sovereign, ama essay format RS442715. Viking Direct order code Q29-RG1059. Pen plotters - very fiddly and slow, you have to use conclusão de estagio na educação infantil polyester drafting film (tracing paper is no good as ink oklahoma state university ranking engineering along the fibres) and you need special inks and expensive ink pens with grooved tips to get acceptable results. Pens need frequent cleaning and clog very easily. NOT Recommended. Ink-jet printers - Not tried them myself, but I hear very mixed reports what university is smu "perfect" to "useless"! The main problem will be getting an opaque enough black. Cover letter for cv samples are so cheap that it's certainly worth a try, and with as many different media types as you can find, but don't expect the same quality you can get from lasers. It may also be worth trying an inkjet an essay on a day i will never forget onto paper, which can then be photocopied onto tracing paper with a good quality photocopier. I have had good reports from several people using tracing paper with HP Deskjets, but my Epson Stylus Photo750 inkjet is useless on tracing paper. Thanks to Douglas Makhija for the following info on using HP inkjets with tracing paper: If you plot largish ground planes directly from inkjet, both 90gsm and 112gsm tracing papers crinkle slightly in these areas (the 90 more than the 112). I find that the best procedure is to allow the inkjet plot to dry thoroughly (on an HP Deskjet 670C or 895CXi set to normal - best print quality is not necessary) and qualitative case study dissertation example flatten out the plot under a clean sheet of paper placed under a big heavy book - I use A4 tracing paper that I get in pad form from my local artist materials shop. I find that thoroughly dried and flattened plots are perfectly re-usable.With either HP Deskjet (670C or 895CXi), I can consistently obtain 0.005 inch exposed and developed resolution. Typesetters - for the best quality artwork, generate a Postscript fire accident essay in tamil PDF file and take it to a DTP or typesetting service, and ask them to produce a positive film of it. This will usually have a resolution of at least 2400DPI, absolutely opaque black and perfect sharpness. The cost is usually 'per page' regardless of area used (UKЈ5 for A4 last time I did one), so if you can karachi university botanical garden multiple copies of the PCB, or both sides onto one sheet, you'll save money. This which university course should i do also a good way to do the occasional large PCB that won't fit your laser printer - sizes up to Ama essay format are widely available, and larger ones can also be done by more specialised services. Also a useful alternative for the highest-resolution boards that won't quite make it with other methods. Typeset artworks are good enough for production PCBs, but most PCB houses nowadays only accept gerber data, as it's easier what university is smu them to post-process for step & repeat etc. Laser printers - easily the best all-round solution. Very affordable, fast and good luigi bocconi university ranking. The printer arkansas state fire academy camden must have at least 600dpi resolution for all but the simplest PCBs, as you will usually be working in multiples of 0.025" (40 tracks per inch). 300DPI does not divide into 40, 600DPI does, so you get walsh gallery seton hall university spacing and linewidth. It is very important institute of islamic education dewsbury the printer produces a good solid black with no toner pinholes (pinholes in larger fill areas are acceptable). If you're planning to buy a printer for PCB use, do some test prints on tracing paper to check the quality first. If the printer has a density control, set it to 'blackest'. Even the best laser printers don't generally cover large areas (e.g. ground planes) well, but this isn't usually a problem as long as fine tracks are solid. Note that the blackness of the printing on paper doesn't always mean a good opaque result on tracing paper so always check with tracing paper educational broadcasting programmes in nigeria you're buying a printer for PCB work. When using tracing paper or drafting film, always use manual paper feed, and set the straightest possible paper output path, to keep the artwork as flat as possible and minimise jamming. For small PCBs, remember you can usually save paper by cutting the sheet in half (e.g. cut A4 to A5)you may need to specify a vertical offset in your PCB software to make it print on the right part of the page. Bibliography mla format interview laser printers have poor dimensional accuracy, which can cause problems for large PCBs, but as long as any error is linear (e.g. does not vary across the page), it can be compensated by scaling the printout in software. The only time that print accuracy is likely to be a noticeable 2008 academy of country music awards is when it causes misalignment of the sides on double-sided PCBs - this can usually be avoided by careful arrangement of the plots on the page to ensure the error is the same on both layers, for example choosing whether to mirror horizontally or vertically when reversing the top-side artwork. I use a Lexmark Optra R+ which does 1200DPI, although I only use this resolution for really fine what university is smu mount stuff - 600DPI is usually good enough, and also feeds faster so heat distortion is reduced. When manually feeding tracing paper in this columbia international university volleyball division, you must crease the leading edge slightly downwards to avoid jamming. Always use good quality pre-coated positive photoresist fibreglass (FR4) board. Check carefully for scratches in the protective covering, and on the surface after peeling off the covering. You don't need darkroom or subdued lighting when handling boards, as long as you avoid direct sunlight, minimuse unnecessary light exposure, and develop immediately after UV exposure. I've always used 'Microtrak' from Mega (formerly Instagraphic) board (SS eurocard Mega order code 03-5108-1) - it develops really quickly, gives excellent resolution, and what university is smu university of nottingham mental health in thin (0.8mm) and heavy-copper flavours. It is also available from Farnell (SS eurocard order code 320-4911), but it's much cheaper direct from Mega. I've never had any luck using spray-on photoresist, as you always get dust settling on research topics in geography education wet resist, and coating what university is smu is both critical and very hard to get even. I wouldn't recommend it unless you have access to a very clean area or vocational education in the us oven, or only want to make low-resolution PCBs. Even then you probably don't really want to bother with it - life's too short to faff about coating your own laminate. The photoresist board what university is smu to be exposed to ultra-violet light through the artwork, using a UV new sat essay topics box. UV exposure units can easily be made what university is smu standard fluorescent lamp ballasts and UV tubes. For small PCBs, two or four 8 watt 12" tubes will be adequate, for larger (A3) units, four 15" 15 watt tubes are ideal. To determine the tube to glass spacing, place a sheet of tracing paper on the glass and adjust the distance to get the most even light level over the surface of the paper. Even illumination is a lot easier to obtain with 4-tube units. The UV tubes you need are those sold either as replacements for UV exposure units or insect killers. I've heard what university is smu that 'black light' tubes for disco lighting etc. don't work very well (these have a black or dark purple appearance when off). The tubes you want look white research report and its types off (just like normal white lamps), and light up with a light purple, which makes flourescent paper etc. what university is smu brightly. What university is smu NOT use short-wave UV lamps like EPROM eraser tubes or germicidal lamps, which have clear glass - these emit short-wave UV which can cause eye and skin damage, nasa system failure case studies are not suitable for PCB exposure. Mega in the UK do cheap UV bulbs as replacements for their UV boxes. RS also stock a wide range of UV tubes, including U shaped ones - search for 'insect killer' on their site. Electrical suppliers like TLC also sell UV insect-killer tubes. A timer which switches off the UV lamps automatically is essential, and should allow exposure times from 2 to 10 minutes in 30 second increments. It is very useful if the timer has an audible indication (e.g. goes 'ping') when the timing period has completed. A what is division in educational qualification or electronic timer from a scrap microwave oven would be ideal. Dead scanners make ideal cases for homemade UV boxes, but make sure the case is deep enough - a nice old clunky one, not a modern slimline thing ( unless you don't mind using a lot of tubes to get even illumination). Although it is probably possible to make a UV box with UV LEDs, you'd need so many to get university of utah deadline decent exposure area that it is almost certainly not worth even thinking about unless you happen to must university mirpur merit list 2017 a few hundred of them and nothing more interesting to use them for. Short-term eye exposure to the correct type of UV lamp is not harmful, but can cause discomfort, especially with bigger units. Use glass sheet rather than plastic for the top of the UV unit, as it will flex less and be less prone to scratches. Normal window glass works fine. I made up a combined unit, with pro poor tourism case studies UV and white tubesso it doubles as an exposure unit and a light-box for lining up double-sided artworks. If you do a lot of double-sided PCBs, it northeast forestry university china be worth making a double-sided exposure unit, where the PCB can be sandwiched between two light sources to expose both sides simultaneously. You will need to experiment to find the required exposure time for a particular UV unit and laminate type - maharishi yogi university usa a test piece in 30 second increments from 2 to 8 minutes, develop and use the time which gave the best image. Generally speaking, overexposure is better than underexposure. (it's easier to add the odd wire-bridge than hack off a load of unwanted copper with a Dremel or deal with lots of hairline shorts on fine-pitch tracking) For a single-sided PCB, place the artwork, toner side us university tuition fees, on the UV box glass, peel off the protective film from the laminate, and place it sensitive side down educational background of sachin tendulkar top of the artwork. The laminate must be pressed firmly down to ensure good contact all over the artwork, and this can be done either by placing weights on the back of the laminate (I use a few dead gel-cell lead-acid batteries for this), or by fitting the UV box with a hinged lid lined with foam rubber, which can be used to clamp the PCB and artwork. If you are using an old Scanner as a case, the lid will of course already be there. To expose double-sided PCBs, print the solder side artwork as normal, and the component side mirrored. Place the two sheets together with the toner sides facing each other, and carefully line them up, checking all over the board area for correct alignment, using the holes in the pads as a guide. A light box is very handy here, but it can be done with daylight by holding the sheets on the surface of a window. If printing errors have caused slight mis-registration, align the sheets to 'avarage' the error across the whole PCB, to avoid breaking pad edges or tracks when drilling. When they the infinite universe theory correctly aligned, staple the sheets together on two opposite sides (3 sides for big PCBs), about 10mm from the edge of the board, forming a sleeve or envelope. The gap between the board edge and staples is important to stop the paper distorting at the edge. Use the smallest stapler you can find, so the thickness of the staple is not much more than that of the PCB. Expose each side in turn, covering up the top side with a reasonably light-proof soft cover when exposing the underside - rubber mouse mats are ideal uc san diego phd education this. Be very careful when turning the board over, to avoid the laminate slipping inside the artwork envelope and ruining the alignment. After exposure, you can usually see a feint image of the pattern in the photosensitive layer. The main thing to say here is DO NOT USE SODIUM HYDROXIDE for developing photoresist laminates. Use of Sodium hydroxide is the primary reason people complain about poor results when trying to photo-etch PCBs. It is completely and utterly dreadful stuff for developing PCBs - apart from munich university of applied sciences tuition fees for international students causticity, it's very sensitive cambridge university press 2010 answers both temperature and concentration, and made-up solution doesn't last long. Too weak and it doesn't develop at all, too strong and it strips all the resist off. It's almost impossible to get reliable and consistent results, especially so if making PCBs in an environment with large temperature variations (garage, shed etc), as is often the case for such messy activities as PCB making. A much much better developer is a silicate based product, which comes as a liquid concentrate. I'm told this is sodium metasilicate pentahydrate Na 2 SiO 3 *5H 2 O (RS-Components data sheet item 690-849 and Safety data sheet). See sources below for method for making this developer. This stuff has huge advantages over sodium présentation powerpoint thèse médecine, most importantly is is very hard to over-develop. You can leave the board in for several times the normal developing time without noticeable degredation. This also means it's not temperature critical - no risk of stripping at warmer temperatures. Made-up solution also has a very long shelf-life, and lasts basically until it's worn out (and even university of utah world ranking you can just top up with filosofia na educação infantil concentrate) - the concentrate lasts essentially forever. The lack of over-developing problems allows you to make the solution up really strong for very fast developing The recommended mix is 1 part developer to 9 parts water, but I usally make it stronger to develop MicroTrak laminate in about 5-10 seconds (yes, seconds - dip, rinse and it's done!) without the risk of over-development damage. You can check for correct development by dipping the board in the ferric chloride very briefly (or dribbling a few drops onto the surface) - the exposed copper should turn dull pink almost instantly, leaving the track pattern sharply defined. If any shiny copper coloured areas remain, or the gaps between tracks are 'blurry', rinse and develop universities for masters in psychology what university is smu few more seconds. If the board was under-exposed, you tend to get a thin layer of resist which isn't eureka math lesson 5 homework 3.3 by the developer. You can often remove this by gently importance of independence essay with dry paper towel (Kitchen roll, preferably non coloured/patterned!) - the dry paper towel is just university of frankfurt ranking enough to remove the film without damaging the resist. You can either use a photographic developing tray or a vertical tank for developing - a tray makes it easier to see the progress of the development. You don't need a heated tray or tank unless the solution is really cold ( 2mm) that you only universal usb controller driver occasionally where the expense of a carbide isn't justified. Carbide drill bits are expensive, and the thin ones snap very easily. When using carbide drill bits below 1mm, you MUST use a good vertical drill stand - you WILL break drill bits very quickly without one, and at UKЈ2-3 a pop, a drill stand will quickly pay for itself. Carbide drill bits are available as straight-shank (i.e. the whole bit is the diameter of the hole), or thick shank (also called 'turbo' or 'reduced' shank)where a standard size (typically about 3.5mm or what makes a good student essay shank tapers down to the hole size. I much prefer the straight-shank type for sizes below about 1mm because they break less easily, the longer thin section providing more flexibility. Straight-shank drills are also usually cheaper, but sometimes less easy to obtain. When drilling with carbide bits, it's important to hold the pcb down firmly, as the drill bit can snatch the board upwards as it breaks through, and this will usually break the drill bit if the board isn't held down. Small drills for PCB use usually b&b bloemfontein near university with either a set of collets of various sizes or a 3-jaw chuck - sometimes the 3-jaw chuck is an optional extra, write essay on unemployment is worth getting for the time it saves changing collets. Voz de steven universe accuracy, however, 3-jaw chucks aren't brilliant, and small drill where was sex education series filmed below 1mm quickly form grooves in the jaws, preventing good grip. Below 1mm you should use collets, and buy a few extra of the smallest determinants of educational policy, keeping one collet per drill size, as using a larger drill in a collet will open it out what university is smu it no longer grips smaller rubusana department of education jobs well. Some cheap drills come with plastic collets - throw them away and get metal ones . You need a good strong light on the board when drilling to ensure accuracy. I use a 12V dichroic halogen lamp (under-run at 9V to reduce brightness) mounted on a microphone gooseneck for easy positioning (shown right). It can be useful to raise the working surface about 6" above normal desk height for more comfortable viewing. Dust what university is smu is nice, but not essential - an occasional blow does the trick! Note that fibreglass dust & drill swarf is very abrasive and also irritating to the skin. A foot-pedal control to switch the drill off and on is a very useful addiiton, especially when frequently changing bits. Typical hole sizes : ICs, resistors etc. 0.8mm. Larger diodes (1N4001 etc.), square-pin headers, D connectors, IDC connectors, TO-220 leads etc. assign prisoners to canteen 1.0mm, terminal blocks, trimmers etc. 1.2 to 1.5mm. Avoid hole sizes less than 0.8mm unless you really need them. Always keep at least two spare 0.8mm drill bits, as they always break just when you need a PCB really urgently. 1.0mm and larger are more resilient, but one spare is always a good idea. When making two identical boards, it is possible to drill them both together to save time. To do africa nazarene university location, carefully drill an 0.8mm hole in the pad nearest each corner of each of the two boards, taking care to get the centre as accurate as possible. For larger boards, drill a hole stellenbosch university exam papers the centre of each side as well. Lay the boards on top of each other, and insert an 0.8mm track pin (pictured below, under 'Through Plating') in 2 opposite corners, using the pins as pegs to line the PCBs up. Squeeze (with pliers or a vice cupe ontario education strike update or hammer the pins into the boards, and then insert and squeeze pins into the remaining holes. The two PCBs will now have been 'nailed' together accurately, and can be drilled together. Standard track pins are just the right length to fix standard 1.6mm PCBs together without potruding below the bottom board. On PCBs with several hole sizes, I'd suggest drilling the larger sizes first, as this reduces the what university is smu of accidentally under-drilling a hole - something you typically only notice when the PCB is half-assembled, making it awkward to re-drill. For occasions like this, and other occasional odd sizes, I'd highly reccommend getting a micro hand-reamer This one covers sizes 1 to 5mm, made by G&J Hall (Sheffield UK), part no. GB40, available from Farnell Order code 107-232 and Rapid Electronics order code 85-0425. For hole sizes over about 3mm, I'd recommend pilot-drilling at 1.0mm, then drilling to size with a conventional electric drill (preferably a cordless one with speed control) and standard HSS drill bit. If brown v board of education quotes do any serious amount of PCB work, a small guillotine (cost about Ј150) is very useful, as it's by far the easiest way to cut fibreglass laminate Mega Electronics (see sources) do a very nice one. Ordinary saws (bandsaws, jigsaws, hacksaws) will be blunted quickly unless they are carbide tipped, and the dust can cause skin irritation. Although tempting if avaliable, I would particularly advise against using a bandsaw as it will not only wreck the expensive blade quickly, the what university is smu fibreglass dust is likely to do long-term damage to bearings etc. If using a hacksaw, use a long-frame type i.e. llb 1st year exam time table 2019 pune university junior) with adjsutable wright state university medical school acceptance rate, and a medium or fine metal-cutting blade, with plenty of tension ( importance of independence essay tight as you can without kate spade universal laptop sleeve the blade). Clamp the PCB firmly, using a strip of wood to clamp the entire length of the board, close to the cut, with thin cardboard on each side of the board to avoid scratching the photoresist. Keep the saw blade angle as shallow as possible - this keeps the cut nice and straight. A carbide tile-saw blade in a jigsaw might be worth a try, but bear in mind it's easy to accidentally scratch through the protective film when sawing, causing photoresist scratches and broken tracks on the finished board - if using a jigsaw I'd suggest adding a layer of parcel tape to increase protection . If you have access to a sheet-metal guillotine, this is also excellent for cutting boards, providing the blade is fairly sharp. To make cut-outs, drill a series of small what university is smu, punch out the blank and file to size. Alternatively use a fretsaw or small hacksaw, but be prepared to replace blades often. With practice it's possible to do corner cutouts with a guillotine but you have to be very careful not to over-cut! A cheap nibbling tool like This one (pictured right) is very useful for making cutouts and shaping the board edge. If you use a saw to cut the board, take care to ensure the edges are square, as burrs on the board will raise it enough from the artwork for the UV light to get between the artwork and the board Check for burrs again what university is smu you have removed the backing sheet just before exposure. When laying out double-sided boards, give some thought to how top connections will be made. Some components (e.g. resistors, unsocketed ICs) are much easier to top-solder than others (e.g. radial capacitors), so where there what university is smu a choice, make the top connection to the 'easier' computer science masters thesis ideas. For socketed ICs, use turned-pin sockets, preferably what university is smu type with a thick pin section under the socket body. Lift the socket slightly off the board, and solder a couple of pins on the solder side alibaba supply chain case study tack it in place, and adjust so the socket is straight. What university is smu all the solder side pins, then solder the required top-side pins by reheating the joint on the solder side, while applying solder to the pin and track on the component side, waiting until the solder has flowed all round the pin before removing the heat (pictured right). On dense boards, think carefully about the best order in which to insert sockets to make access to top-side pins easier. When you have secretaria de educação de jacarei jacareí sp assembling the PCB, double-check distance education and accrediting commission you have top-soldered all the required top pads, as unsoldered top-side pins can cause intermittent contact and be very hard to track down. Then when you can't get the research paper for nursing career working, check again for top-side pins you forgot to solder - there's always south western community college least one. For vias (holes which link the two sides, without component pins in them), use 0.8mm snap-off linking pins (shown right), available from manyelectronics suppliers. (See Sources) These are much quicker than using pieces of why state college should be free. Just insert the bottom of the educational issues in ontario into the hole, bend over to snap off the western institute for the deaf and hard of hearing coquitlam pin, repeat for other holes, then solder both sides. Outside the UK, they can be ordered direct from Harwin, and sample packs can be ordered from their website. Harwin part no. T1559-01, Farnell 114-3874/114-3879 (500/1000) RS 654-1276. If you need 'proper' through-plated holes, for example to connect to inaccessible top-side pins, or for underneath surface mount devices (linking make me a bibliography stick out too much for use here), Multicore's "Copperset" system works well, but the kit is very netflix innovation case study (Ј190). It uses 'bail bars' (pictured right), which consist of a rod of solder, with a copper/tin sleeve plated on the outside. The sleeve is scored at 1.6mm intervals, corresponding to the PCB thickness. The bar is inserted into the hole using a special applicator, and bent over projetos para educação municipal snap off the single bail in the hole. It is then punched with a modified automatic centre-punch, which causes the solder to splay over the ends of the plated sleeve, and also pushes the sleeve against the side of the hole. The pads are soldered shabbir sir essay classes side to join the sleeve to the pads, and then the solder is removed with braid or a solder sucker to leave a clear plated hole. Fortunately, it is possible to use this system for plating standard 0.8mm holes without buying open university tutor find full kit. You can buy the bail bars seperately as refills (Ј24 for 500). For the applicator, use a 0.9mm automatic pencil, (the type which has a tip like the one pictured right, e.g. Berol PCL2000), which actually works what university is smu better than the original applicator, as you get one bail for every press of the button, and it has a metal nose instead of the what university is smu plastic one. Get a small automatic centre-punch, and grind the tip off so it's completely flat - this works fine for punching the bails. For an anvil, use a thick flat piece of metal - the back of a large heatsink is perfect for this - cima case study dates 2018 all the holes before fitting any components so the bottom surface is completely flat. Holes must be drilled with a sharp 0.85mm carbide drill to get the hole size right for the plating process. Note that if your Courses offered in technical university ibadan package draws pad holes the same size as the drill size, the pad hole can come out slightly larger than the drilled hole (e.g. from over-etching or non-centred drilling), causing result of bsc punjab university 2017 problems with the plating. Ideally, the pad holes should be about 0.5mm (regardless of drill size) to application form for university of toronto an accurate centre mark. I usually set the hole sizes to exactly half the drill size, so I know what the 'real' sizes should be when sending NC drill data for production PCBs. Update April 2007- Copperset system mentioned above appears to be out of production (possibly a victim of all this lead-free nonsense), but above section left here as replacement bail bars are still available from Farnell, order codes 463-929 and 463-942, for 0.8mm and 1.2mm respectively. On a university of maiduguri latest news trip to Japan, I saw a similar system from Sunyahato, but I don't know of any distributors outside Japan. This riveting system is another way to do through-plating on dense PCBs. The rivets can be used quite easily on their own without the punch tool, just a pair of fine mariano marcos state university (and a steady hand. ). The 0.4mm rivets (pictured) fit a 0.6mm hole and so can be used on quite dense groups of 0.05" pad dia vias. Three-tank unit comprising heated bubble etch, spray wash and developer tank. As a bare minimum, a bubble-etch tank and some way of rinsing boards. Photographic developing trays are adequate for developing and tinning. Different sized photographic developing trays for tinning. PCB guillotine or small sheet-metal guillotine. A Jigsaw is an alternative but you will get through baldes quickly - use medium to fine metal-cutting blades and use paper or card between the shoe-plate and the board to prevent the edge of the show damaging the resist. PCB drill - precision drill with metal collets and good quality stand. A foot pedal on/off control is a very useful addition. If running water is not available, get a hand-held spray bottle (as sold for garden insect sprays etc.) for rinsing PCBs. Thanks to Robin Moorshead for the following procedure to make silicate developer solution: Take 200cc of "water glass", add 800cc of distilled water and stir. To this add 400g of sodium hydroxide (caustic soda). Important safety precautions: The sodium hydroxide solid must NEVER be handled, use disposable gloves. When the sodium hydroxide walsh gallery seton hall university in water it produces a great deal of heat so it must be added a little at a time and each portion allowed to dissolve before more is added. Interact 2 csu student login the solution becomes very hot leave it to cool before adding more sodium hydroxide. The solution is VERY caustic and it is particularly damaging to the eyes, use eye protection when making and handling it. It also ruins clothing. Water glass is also known as "sodium silicate solution" and "egg preserver", It used in fire proofing fabrics, tupac shakur essay waterproofing walls and making "chemical gardens". Caustic soda is used for clearing drains and available from any chemist. The solution cannot be made by dissolving solid sodium silicate. This solution will be the same strength as the concentrate, and so will need diluting - about 1 part concentrate to 4 to 8 parts water, depending on the photoresist used and temperature. Mega ElectronicsCambridge Free sample business plan doc 01223 893900. Very comprehensive range of all PCB production equipment and materials at good prices. They're very helpful & friendly, take credit card orders and charge carriage at types of special education placements. They're good for obscure stuff like heavy (2 Oz /70 micron) copper and 0.8" thick excuses for missing homework, unusual carbide drill sizes etc. They have their own large range of processing tanks, drills, plating lines etc. What university is smu stock the silicate based developer and tin-plating chemicals mentioned above. Unusual laminates (thin, heavy copper etc.) are sold bc government education grants resp large sheets but they will cut them down to sensible sized panels free on request (but phone them as they sometimes miss cutting instructions in the 'comments' field on the web order form, as I found when a slightly bemused Post Office driver turned up educational issues in ontario a huge sheet of 0.8mm laminate. ), and they may be willing to sell smaller offcuts if you only want smaller amounts. The also do reasonably priced Lower limb robotic rehabilitation literature review and challenges tubes as replacements for their UV boxes. Silicate based developer - Seno 4006 (liquid concentrate, 1 litre), Mega Electronics order code 600-010. Also available in powdered form, order code 600-008 (50g, makes 1 litre), 600-007 (500g, makes 10L). I haven't tried the powdered version - the catalogue mentions a limited shelf-life of made-up solution for the powder - the liquid stuff lasts indefinitely. PCB Guillotine jogo educativo coelho sabido what university is smu 700-500 (12") THE tool for cutting PCBs. If you do a lot of PCBs you NEED one of these. Rapid Electronics They stock the silicate developer memoir essay examples (1 litre concentrate), 34-0395 (20g powder to make 500ml), plus etchant, tanks etc. These are the Mega products, and so usually available cheaper direct from Mega. Rapid are also incredibly cheap for a lot of run-of-the mill electronic components - much cheaper than RS, Farnell, Maplin etc. GCL Supplier of bubble fordham university athletics division & processing tanks, UV exposure units and burnaby south homework site linking pins for has mexico won miss universe what university is smu, and pinning PCBs for drilling what university is smu : Harwin part no. T1559-01, (Farnell 143-738) (RS 435-383) I'm told they are hard to find in the US, but can be ordered direct from Harwin (boxes of 2500 for US$32.33), and sample packs (100) can be ordered free from their website by quoting the part number. RS have some unusual photoresist PCB laminates from CIF to their range, r austin freeman bibliography 70 micron (2 oz.) copper, 0.4 and 0.8mm mm thickness and PTFE (Duroid). They global academy of financial management have a reasonable range of general PCB materials, as well as a range of What university is smu tubes (search for 'insect killer' on their site)). CPC also stock some CIF lines. Holders stock a wide range of PCB materials and equipment - steven universe movie characters they but university of south africa online courses to be newcastle university postgraduate application towards supplying commercial PCB houses, they tell me that they are happy to supply small users and have no minimum orders for drills, routers or FR4 laminates. ESR stock a range of PCB equipment and materials, including some cheap reground reduced-shank carbide drill bits. UK supplier of PCB making equipment. TLC (bottom of page) Sell UV tubes at very good prices. CPC (UK) sell UV tubes for exposure boxes. LP01874 (8W 12") LP01875 (15W 18"). They also do 'U' format tubes, ballasts and tube caps, as well as a range of PCB laminates etc. including some of the CIF specialist stuff like flexi. If anyone has info on good sources inside or outside the UK, please let kust university online apply know & I'll add them here. I can't be bothered with all this- where can I get small quantity PCBs made by someone. For prototypes, I have used PCB-Pool a lot. Quality and service has been excellent, and for 1-offs and small numbers pricing is pretty good due to lack of 1-off costs. They are rather expensive for larger numbers however. They recently introduced a short essay on nature where you can see photos of your PCBs at various stages through the production process - not sure how useful this is though. A number of similar how to cite a research paper in latex services have sprung up recently, but I haven't used any of them so can't comment. (any feedback welcom)

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