General PCB basic design process is as follows:

Preliminary preparation →PCB structure design → guide list → rule setting →PCB layout → wiring → wiring optimization and silk screen → network and DRC check and structure check → output light drawing → light drawing review →PCB board production/proofing data →PCB board factory project EQ confirmation → patch data output → project completion.

1: Preparation

This includes preparing package libraries and schematics. пре Дизајн ПЦБ-а, we should first prepare the logic package of schematic SCH and the package library of PCB. Библиотеке пакета могу доћи са ПАДС -овима, али је тешко пронаћи одговарајуће библиотеке уопште. Најбоље је да направите сопствене библиотеке пакета према стандардним подацима о величини изабраних уређаја. In principle, the PCB packaging library should be done first, and then the SCH logic packaging should be done. Библиотека амбалаже од ПЦБ -а има високе захтеве, што директно утиче на инсталацију плоче; SCH logical packaging requirements are relatively loose, as long as the definition of pin attributes and the corresponding relationship with PCB packaging on the line. PS: Note the hidden pins in the standard library. Затим је шематски дизајн, спреман за дизајн ПЦБ -а.

2. PCB structure design

У овом кораку, према величини штампане плоче и механичком позиционирању, површина ПЦБ плоче се исцртава у окружењу дизајна ПЦБ -а, а конектори, дугмад/прекидачи, рупе за завртње, монтажне рупе и тако даље постављају се према захтевима за позиционирање. And fully consider and determine the wiring area and non-wiring area (such as how much of the screw hole around the non-wiring area).

3: табела мрежних водича

It is recommended to route the net table into the board frame first. Import a board enclosure in DXF format or EMN format

4: Rule setting

Reasonable rules can be set according to the specific PCB design. These rules are PADS constraint managers, which can be used to restrict line width and safe spacing at any point in the design process. Non-conforming areas are marked by DRC Markers during SUBSEQUENT DRC testing.

The general rule setting is placed before the layout, because sometimes some fanout work needs to be completed during the layout, so the rules should be set well before the FANout. When the design project is larger, the design can be completed more efficiently. Напомена: правила су постављена за бољи и бржи дизајн, другим речима, ради погодности дизајнера. Уобичајене поставке су: 1. Подразумевана ширина линије/проред за уобичајене сигнале. Изаберите и поставите рупу. 3. Подесите ширину линије и боју важних сигнала и извора напајања. 4. Board layer Settings.

5: PCB layout

Need to pay special attention to, in place of components, components should be considered when the actual size (in the area and height) and the relative position between the components, to ensure that the electrical properties and production of circuit board installation convenience and feasible sex at the same time, should be on the premise of guarantee the above principle to reflect, appropriate change device, make it tidy and beautiful, На пример, исти уређај треба поставити уредно и у истом смеру, а не „насумично разбацани“. This step concerns the difficulty of board integral figure and next wiring degree, want to spend big effort to consider so. When layout, can make preliminary wiring first to not quite affirmative place, sufficient consideration.

6: wiring

Ожичење је најважнији процес у дизајну ПЦБ -а. Ово ће директно утицати на перформансе ПЦБ плоче. У процесу пројектовања ПЦБ -а, ожичење генерално има три нивоа поделе: први је дистрибуција, што је најосновнији захтев дизајна ПЦБ -а. If the line is not cloth, get everywhere is flying line, it will be a unqualified board, can say that there is no entry.

Друго је задовољство електричним перформансама. Ово је стандард за мерење да ли је штампана плоча квалификована. This is after the distribution, carefully adjust the wiring, so that it can achieve the best electrical performance. Затим постоји естетика. Ако је ваша жица повезана, такође немојте имати место које утиче на перформансе електричних апарата, али гледајте мимо себе, додајте шарене, јарко обојене боје, које рачунају како су перформансе вашег електричног апарата добре, и даље будите смеће у туђим очима. This brings great inconvenience to testing and maintenance. Ожичење би требало да буде уредно и уједначено, а не укрштено без правила. Све ово треба постићи у контексту осигурања електричних перформанси и испуњавања других индивидуалних захтева, у супротном се мора напустити суштина.

Wiring is mainly carried out according to the following principles: (1) In general, the power line and ground wire should be wired first to ensure the electrical performance of the circuit board. In the scope of conditions allow, as far as possible to widen the width of power supply, ground wire, the best ground wire is wider than the power line, their relationship is: ground wire > power line > signal line, usually signal line width is: 0.2 ~ 0.3mm (about 8-12mil), the narrowest width up to 0.05 ~ 0.07mm (2-3mil), the power cord is generally 1.2 ~ 2.5mm (50-100mil). The PCB of a digital circuit can be used as a circuit with wide ground conductors, that is, a ground network (analog circuit ground cannot be used in this way). (2) in advance to the more strict requirements of the line (such as high frequency line) wiring, input and output side line should avoid adjacent parallel, so as not to produce reflection interference. When necessary, ground wire should be added to isolate, and the wiring of two adjacent layers should be perpendicular to each other, which is easy to produce parasitic coupling in parallel. (3) the oscillator shell is grounded, and the clock line should be as short as possible, and it can’t be everywhere. Below the clock oscillation circuit, the special high-speed logic circuit should increase the area of the ground, and should not go to other signal lines, so that the surrounding electric field tends to zero;

(4) Use 45° broken line wiring as far as possible, not 90° broken line, in order to reduce the radiation of high-frequency signal; (5) Any signal line should not form a loop, if unavoidable, the loop should be as small as possible; Сигнална линија кроз отвор треба да буде што је могуће мања; (6) The key line should be as short and thick as possible, and protective ground should be added on both sides. (7) when transmitting sensitive signals and noise field signals through flat cables, it is necessary to use the way of “ground line – signal – ground line”. (8) Test points should be reserved for key signals to facilitate production and maintenance testing. (9) After schematic wiring is completed, wiring should be optimized; At the same time, after the preliminary network check and DRC check is correct, the ground wire is filled in the area without wiring, and a large area of copper layer is used as ground wire, and the unused places are connected with the ground as ground wire on the printed board. Или направите вишеслојну плочу, напајање, линија уземљења заузимају сваки слој.

(1) Line Generally, the signal line width is 0.3mm(12mil), and the power line width is 0.77mm(30mil) or 1.27mm(50mil); The distance between wire and wire and between wire and pad should be greater than or equal to 0.33mm(13mil). In practical application, it should be considered to increase the distance when conditions permit; When the cabling density is high, it is advisable (but not recommended) to use two cables between IC pins. The width of the cables is 0.254mm(10mil), and the distance between the cables is not less than 0.254mm(10mil). Under special circumstances, when the pin of the device is dense and the width is narrow, the line width and line spacing can be appropriately reduced. (2) ПАД (ПАД) ПАД (ПАД) и прелазна рупа (ВИА) основни захтеви су: пречник диска од пречника рупе је већи од 0.6 мм; For example, universal pin type resistors, capacitors and integrated circuits, using disk/hole size 1.6mm /0.8mm (63mil/32mil), socket, pin and diode 1N4007, using 1.8mm/1.0mm (71mil/39mil). In practical application, it should be determined according to the size of the actual components. If conditions are available, the size of the pad can be appropriately increased. Отвор за инсталацију компоненти дизајнираних на штампаној плочи требао би бити око 0.2 ~ 0.4 мм (8-16мил) већи од стварне величине пинова компоненти. (3) Перфорација (ВИА) је генерално 1.27 мм/0.7 мм (50мил/28мил); When the wiring density is high, the hole size can be appropriately reduced, but not too small, can consider 1.0mm/0.6mm(40mil/24mil). PAD and VIA: ≥ 0.3mm (12mil) PAD and PAD: ≥ 0.3mm (12mil) PAD and TRACK: ≥ 0.3mm (12mil) TRACK and TRACK: ≥ 0.3mm (12mil) ≥ 0.3mm (12mil) PAD and VIA: ≥ 0.254mm (10mil) PAD and TRACK: ≥ 0.254mm (10mil) PAD and TRACK: ≥ 0.254mm (10mil) TRACK and TRACK: ≥ 0.254mm (10mil)

7: wiring optimization and screen printing

“Нема најбољег, само боље”! Без обзира колико труда уложили у дизајн, када завршите, погледајте га поново, и даље ћете осећати да можете много тога да промените. Опште правило дизајна је да оптимално ожичење траје два пута дуже од почетног ожичења. Након што осетите да ништа не треба мењати, можете положити бакар. Полагање бакра углавном поставља жицу за уземљење (обратите пажњу на одвајање аналогног и дигиталног уземљења), можда ће вишеслојна плоча такође морати положити напајање. За сито штампање треба обратити пажњу да нас уређај не блокира нити уклони рупом и подлогом. У исто време, дизајн према површини компоненте, дно речи треба да буде огледало, како се не би збунио ниво.

8: Network, DRC and structure inspection

Before light painting, it is generally necessary to Check. Every company has its own Check List, including the requirements of principle, design, production and other links. The following is an introduction to the two main inspection functions provided by the software. ДРЦ провера:

9: output light painting

Before the output of light painting, ensure that the veneer is the latest version that has been completed and meets the design requirements. The output file of light painting is used for the production of board in the plate factory, the production of steel net in the steel net factory, and the production process file in the welding factory.

The output files are as follows (take the four-layer board as an example) : 1). Wiring layer: refers to the conventional signal layer, mainly wiring. Називају се Л1, Л2, Л3 и Л4, при чему Л представља слој слоја ожичења.

2). Screen printing layer: refers to the layer in the design document that provides information for the processing of screen printing. Usually, there will be top screen printing and bottom screen printing if there are devices or marks on the top and bottom layer. Именовање: горњи слој се зове СИЛК_ТОП; The underlying name is SILK_BOTTOM.