Thiết kế mạch dùng Protel

Vẽ mạch nguyên lí trong Protel 99 SE1.Giới thiệu một số menu của Protel 992.Một số thao tác khi vẽ mạch nguyên líII.Vấn đề bảo mật trong Protel 99 SE1.Đăng kí tài khoản cho các thành viên2.Hạn chế quyền truy nhập vào bản thiết kế3.Tạo mới, mở, ghi lại một mạch inIII.Vẽ mạch in trong Protel 99 SE1.Chuyển đổi đơn vị đo2.Di chuyển nhanh con trỏ4.Đo khoảng cách trong không gian mạch in5.Kiểu chân (Footprint) của một số linh kiện thông dụng6. Thay đổi độ rộng của từng đường dây trong mạch in7.Chuyển từ mạch nguyên lí sang mạch in8.Chuyển...
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Thiết kế mạch dùng Protel A GUIDELINE ON PRINTED CIRCUIT BOARD DESIGN for YEAR 3 AND 4 ENGINEERING STUDENTS UNIVERSITY of AUCKLANDDEPARTMENT of ELECTRICAL AND ELECTRONIC ENGINEERING BY FRED NASSENSTEIN DEC 1992 UPDATED MAR 1995 UPDATED DEC 1996 BY SLAVEK PRZEPIORSKI Libray List Open Protel list THE COMPLETE PROCESS OF CIRCUIT DESIGN1. SCHEMATIC DESIGN ------------ CAD2. PCB DESIGN------------------------- ---------3. ARTWORK PLOT------------------4. MASK (NEGATIVE)5. BOARD EXPOSURE---------------- - DEVELOPING---------------------- ---CHEMICAL PROCESS - ETCHING---------------------------- - PHOTORESITS REMOVAL-----6. TINNING7. DRILLING8. BOARD ASSEMBLING9. TESTINGProcess 2 to 6 are briefly mentioned in this guideline . The work involved with process4 to 6 is usually carried out by a technician in this department.Contents:1. - Introduction2. - Chemical Process3. - Computer Aided Design4. - Using PROTEL-PCB5. - Example6. - Appendix7. - Library PartsINTRODUCTIONHaving gone through the process and struggle to design an electronic circuit,which should result in the form of a circuit diagram, you have reached the stageof needing to create your circuit at a physical level. Printed circuit board designcould be difficult as well, since you may include mistakes from your circuitdiagram and possibly create some more with this procedure (unless you are verycareful). But relax creating a PCB could (hopefully) be a nice expression of yourtechnical capabilities as well as an expression of your artistic skills.A PCB is the most common, practical, reliable and low cost (in particular forlarger quantities) solution to assemble a cluster of electronics components (see #1other techniques). The aim of PCB design is to physically place and interconnect(using conductive tracks acting as wires) electronic components on an insulatingmaterial according to the plans in the circuit diagram (or schematic).CHEMICAL PROCESSIn practice we do not actually print the physical circuit on a board, this is usuallyachieved by means of a photographic and chemical process (see #2 for othertechniques).The board is usually made of a glass fibre strengthened epoxy based material(sheet) with good electrical and mechanical properties (ie.: good insulator andhigh mechanical strength).The epoxy board is covered with a very thin copper layer either on one (singlesided boards) or on both sides (double sided boards) which we have to configurein such a way so that the copper can be used as individual conductors (see #3 formulti layers). This is usually achieved with the aid of an additional UV lightsensitive photo resist (plastic film) attached to the surface of the copper layer (seefigure 1).By exposing the photo resist with Ultra Violetlight the resist will stabilise andremain unstabilized for the areas not exposed.With the use of a developing process (similarto normal film processing) we are then able toremove the unexposed photo resist areas Fig.1.leaving the exposed areas which will act as aprotective film for the etching process.By placing this board into an etchingsolution (acid) we are able to etch (remove). Finally with the aid of a solvent we have toremove the photo resist so that the copper can be soldered on to. Usually the coppersurface will be roller tinned or sprayed with a solder lacquer to improve the solderingand to avoid corrosion.It is obvious that with the above described process we are able to create anyshape of a conductive structure and thus electrical connections on an insulatingmaterial. To obtain the desired structure necessary for our circuit design howeverwe need to generate a MASK or NEGATIVE (black on transparent film) whichwe have to place between our film coated board and the UV light exposure unit.COMPUTER AIDED DESIGN (CAD)In the Electrical and Electronics Engineering Department there are several PCBsoftware packages available on the network able to produce the artwork for sucha mask. In this session however I will only outline the use of PROTEL-WINDOWS since it is easy to use and performs very well for most designs.At present we use the above software to create a PLOT ARTWORK FILE inPostcript format which can be send to an outside firm (ie.:BTL Technologies).This company is able to produce a high resolution negative film necessary for thefinal MASK and manufacturing process of the PCB (see #4 for othertechniques). Before going further in to detail in how to use the PCB software,you should consider the following:1- KEEP THE TRACK LENGTH SHORT AND WIDEThe c ...