PCB awọn ọna wiwu tẹsiwaju lati ni ilọsiwaju, ati awọn imuposi wiwa rọ le dinku gigun okun waya ati laaye aaye PCB diẹ sii laaye. Wiwa PCB ti aṣa jẹ opin nipasẹ awọn ipoidojuko okun ti o wa titi ati aini awọn okun onigun lainidii. Yiyọ awọn idiwọn wọnyi le mu ilọsiwaju didara didara pọ si ni pataki.

Let’s start with some terminology. A ṣalaye asọye Angle lainidii bi wiwa waya nipa lilo awọn apa Angle lainidii ati awọn radians. O jẹ iru okun waya, ṣugbọn kii ṣe opin si lilo iwọn 90 nikan ati awọn ipele laini Angle 45. Topological wiring is wire wiring that does not adhere to grids and coordinates and does not use regular or irregular grids like shape-based wiring. Jẹ ki a ṣalaye ọrọ wiwa rọ bi okun waya laisi apẹrẹ ti o wa titi ti o jẹ ki iṣapẹẹrẹ apẹrẹ akoko-akoko gidi lati ṣaṣeyọri awọn iṣeeṣe iyipada atẹle. Awọn arcs nikan lati awọn idiwọ ati awọn tangents ti o wọpọ ni a lo lati ṣe apẹrẹ laini. (Obstacles include pins, copper foil, forbidden areas, holes and other objects) part of the circuit of two PCB models. Awọn okun waya alawọ ati pupa n ṣiṣẹ lori awọn fẹlẹfẹlẹ oriṣiriṣi ti awoṣe PCB. The blue circles are the perforations. The red element is highlighted. There are also some red round pins. Use only line segments and models with an Angle of 90 degrees between them. Nọmba 1B jẹ awoṣe PCB nipa lilo awọn aaki ati awọn igun lainidii. Wiring at any Angle may seem strange, but it does have many advantages. The way it is wired is very similar to how engineers wired it by hand half a century ago. Ṣe afihan PCB gidi kan ti o dagbasoke ni ọdun 1972 nipasẹ ile -iṣẹ Amẹrika kan ti a pe ni Digibarn fun wiwọ ọwọ pipe. This is a PCB board based on Intel8008 computer. Lainidii Angle relays ti o han ni Nọmba 2 jẹ iru kanna. Kilode ti wọn yoo lo wiwadii Angle lainidii? Nitori iru wiwa yii ni ọpọlọpọ awọn anfani. Arbitrary Angle wiring has many advantages. Ni akọkọ, kii ṣe lilo awọn igun laarin awọn apakan laini fi aaye PCB pamọ (awọn polygons nigbagbogbo gba aaye diẹ sii ju tangents). Traditional automatic cablers can place only three wires between adjacent components (see left and center in Figure 3). Bibẹẹkọ, nigbati wiwa ni igun eyikeyi, aaye to wa lati fi awọn okun onirin 4 si ọna kanna laisi irufin ṣiṣewadii ofin apẹrẹ (DRC). Ṣebi a ni moderún ipo rere ati pe a fẹ sopọ awọn pinni chiprún si awọn pinni meji miiran. Using only 90 degrees takes up a lot of space. Lilo wiwọn Angle lainidii le kuru aaye laarin eerun ati awọn pinni miiran, lakoko ti o dinku ifẹsẹtẹ. In this case, the area was reduced from 30 square centimeters to 23 square centimeters. Yiyi chiprún ni eyikeyi igun tun le pese awọn abajade to dara julọ. In this case, the area was reduced from 23 square centimeters to 10 square centimeters. It shows a real PCB. Arbitrary Angle wiring with rotating chip function is the only wiring method for this circuit board. Eyi kii ṣe imọ -jinlẹ nikan, ṣugbọn tun ojutu ti o wulo (nigbamiran ojutu nikan ti o ṣeeṣe). Shows an example of a simple PCB. Awọn abajade topology cabler, lakoko awọn abajade adaṣe adaṣe adaṣe ti o da lori apẹrẹ ti o dara julọ jẹ awọn fọto ti PCB gangan. An automatic cabler based on optimal shape cannot do this because the components are rotated at arbitrary angles. O nilo agbegbe diẹ sii, ati pe ti o ko ba yi awọn paati pada, ẹrọ naa ni lati jẹ ki o tobi. Iṣẹ ṣiṣe ipilẹṣẹ yoo ni ilọsiwaju pupọ laisi awọn abala ti o jọra, eyiti o jẹ orisun igbagbogbo. The level of crosstalk increases linearly as the length of parallel wires increases. As the spacing between parallel wires increases, crosstalk decreases quadratic. Let’s set the level of crosstalk produced by two parallel 1mm wires spaced d to e. Ti Angle ba wa laarin awọn apakan okun waya, lẹhinna bi Igun yii ṣe n pọ si, ipele crosstalk yoo dinku. The crosstalk does not depend on the length of the wire, but only on the Angle value: where α represents the Angle between the wire segments. Wo awọn ọna wiwa mẹta wọnyi atẹle. On the left side of Figure 8 (90 degree layout), there is the maximum wire length and the maximum emi value due to parallel line segments. In the middle of Figure 8 (45 degree layout), the wire length and emi values are reduced. On the right-hand side (at any Angle), the wire length is shortest and there are no parallel wire segments, so the interference value is negligible. So arbitrary Angle wiring helps to reduce the total wire length and significantly reduce electromagnetic interference. You also remember the effect on signal delay (conductors should not be parallel and should not be perpendicular to the PCB fiberglass). Advantages of flexible wiring Manual and automatic movement of components does not destroy the wiring in flexible wiring. Onitumọ naa ṣe iṣiro apẹrẹ ti aipe ti okun waya ni adaṣe (ni akiyesi ifasilẹ aabo to wulo). Iṣakojọpọ ti o rọ le nitorina dinku akoko pupọ ti o nilo lati satunkọ topology, ni dara julọ ṣe atilẹyin ifilọlẹ pupọ lati pade awọn idiwọ. Eyi fihan apẹrẹ PCB kan ti o gbe nipasẹ awọn iho ati awọn aaye ẹka. Lakoko išipopada adaṣe, awọn aaye ẹka okun waya ati awọn iho-nipasẹ ni a tunṣe si ipo ti o dara julọ. In most computer-aided design (CAD) systems, the wiring interconnection problem is reduced to the problem of sequentially finding paths between pairs of points in a maze of pads, forbidden areas, and laid wires. Nigbati a ba rii ipa -ọna kan, o wa titi ati di apakan ti iruniloju. Alailanfani ti sisẹ sisọ ni pe abajade wiwakọ le dale lori aṣẹ wiwa. Nigbati didara topological tun jinna si pipe, iṣoro “didi” waye ni awọn agbegbe kekere ti agbegbe. But no matter which wire you rewire, it’s not going to improve the quality of the wiring. This is a serious problem in all CAD systems using sequential optimization. This is where the bending elimination process is useful. Fifun waya n tọka si iyalẹnu pe okun waya ninu nẹtiwọọki kan gbọdọ rin kakiri ohun kan lori nẹtiwọọki miiran lati wọle si ohun kan. Rewiring a wire will not correct this. Apẹẹrẹ ti atunse ni a fihan. A lit red wire travels around a pin in the other network, and an unlit red wire connects to this pin. Awọn abajade ṣiṣe adaṣe ni a fihan. In the second case (on another layer), a lighted green wire is automatically rewired by changing the wiring layer (from green to red). Eliminate wire bending by automatically optimizing wire shape (approximate arcs with line segments just to show any Angle examples without arcs). (top) original design, (bottom) after eliminating bending design. Red onirin ti wa ni afihan. Ninu igi Steiner, gbogbo awọn laini gbọdọ wa ni asopọ bi awọn apakan si awọn igun (awọn ipari ati awọn afikun). Ni oke ti fatesi tuntun kọọkan, awọn apakan mẹta gbọdọ pejọ ko si ju awọn ipele mẹta lọ gbọdọ pari. The Angle between the line segments that converge to the vertex shall not be less than 120 degrees. Ko ṣoro pupọ lati kọ Steiner kan pẹlu awọn ohun -ini majemu ti o to, ṣugbọn kii ṣe dandan kere. Gray Steiner trees are not optimal, but black Steiner trees are. Ninu apẹrẹ ibaraẹnisọrọ ti o wulo, awọn iru awọn idiwọ oriṣiriṣi gbọdọ wa ni ero. Wọn fi opin si agbara lati kọ awọn igi ti o kere ju ni lilo awọn alugoridimu mejeeji ati awọn igi Steiner ni lilo awọn ọna jiometirika. The obstacles are shown in gray and we recommend starting at any end vertex. If there is more than one adjacent terminating vertex, you should choose one that allows you to continue using the second vertex. It depends on the Angle. Ilana akọkọ nibi jẹ alugoridimu ti o da lori agbara ti o ṣe iṣiro awọn ipa ti n ṣiṣẹ lori awọn igun tuntun ati leralera gbe wọn lọ si aaye iwọntunwọnsi (titobi ati itọsọna ti awọn ipa da lori awọn okun waya ni awọn aaye ẹka ti o wa nitosi). Ti Igun laarin awọn abala laini meji ti o sopọ si fatesi (ipari tabi afikun) kere si awọn iwọn 120, aaye aaye kan le ṣafikun, lẹhinna alugoridimu ẹrọ kan le ṣee lo lati mu ipo ipo fatesi pọ si. It’s worth noting that simply sorting all angles in descending order and adding new vertices in that order doesn’t work, and the result is worse. After adding a new node, you should check the minimum of a subnet consisting of four pins:

1. If a vertex is added to the vicinity of another newly added vertex, check for the smallest four-pin network.

2. If the four-pin network is not minimal, select a pair of “diagonal” (belonging to the quadrilateral diagonal) endpoints or virtual terminal nodes (virtual terminal nodes – wire bends).

3. The line segment that connects the endpoint (virtual endpoint) to the nearest new vertex is replaced by the line segment that connects the endpoint (virtual endpoint) to the distant new vertex.

4. Use mechanical algorithms to optimize vertex positions.

This method does not guarantee to build the smallest network, but compared with other methods, it can achieve the smallest network length without grazing. O tun ngbanilaaye fun awọn agbegbe nibiti a ti fi ofin de awọn isopọ ipari, ati nọmba awọn apa ipari le jẹ lainidii.

Flexible wiring at any Angle has some other interesting advantages. For example, if you can automatically move many objects with the help of automatic real-time wire shape recalculation, you can create parallel serpentine lines. This cabling method makes better use of space, minimizes the number of iterations, and allows for flexible use of tolerances. If there are two serpentine lines interlaced with each other, the automatic cabler will reduce the length of one or both, depending on rule priority.

Consider the wiring of BGA components. In the traditional peripheral-to-center approach, the number of channels to the periphery is reduced by 8 with each successive layer (due to a reduction in perimeter). For example, a 28x28mm component with 784 pins requires 10 layers. Diẹ ninu awọn fẹlẹfẹlẹ ninu aworan atọka ti salọ wiwakọ. Olusin 16 fihan mẹẹdogun ti BGA kan. Ni akoko kanna, nigba lilo ọna wiwakọ “aarin si ẹba”, nọmba awọn ikanni ti o nilo lati jade si ẹba ko yipada lati fẹlẹfẹlẹ si fẹlẹfẹlẹ. Eyi yoo dinku nọmba awọn fẹlẹfẹlẹ pupọ. Fun iwọn paati ti 28x28mm, awọn fẹlẹfẹlẹ 7 ti to. Fun awọn paati nla, o jẹ win-win. Figure 17 shows a quarter of the BGA. An example of BGA wiring is shown. When using the “center to periphery” cabling approach, we can complete the cabling of all networks. Lainidii Angle topological adaṣe adaṣe le ṣe eyi. Traditional automatic cablers cannot route this example. Shows an example of a real PCB where the engineer reduced the number of signal layers from 6 to 4 (compared to the specification). In addition, it took engineers only half a day to complete the wiring of the PCB.