PCB il-metodi tal-wajers ikomplu jitjiebu, u tekniki flessibbli tal-wajers jistgħu jnaqqsu t-tul tal-wajer u jeħilsu aktar spazju tal-PCB. Il-wajers tal-PCB konvenzjonali huma limitati minn koordinati ta ‘wajers fissi u n-nuqqas ta’ wajers angolati b’mod arbitrarju. It-tneħħija ta ‘dawn il-limitazzjonijiet tista’ ttejjeb b’mod sinifikanti l-kwalità tal-wajers.

Let’s start with some terminology. Aħna niddefinixxu wajers tal-Angolu arbitrarji bħala wajers tal-wajer billi nużaw segmenti u radjani tal-Angolu arbitrarji. Huwa tip ta ‘wajers tal-wajer, iżda mhuwiex limitat għall-użu biss ta’ segmenti tal-linja ta ‘Angolu ta’ 90 grad u 45 grad. 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. Ejjew niddefinixxu t-terminu wajers flessibbli bħala wajers tal-wajer mingħajr forma fissa li tippermetti kalkolu mill-ġdid tal-forma tal-wajer f’ħin reali biex tikseb il-possibbiltajiet ta ‘trasformazzjoni li ġejjin. Arki minn ostakli u t-tanġenti komuni tagħhom biss jintużaw biex jiffurmaw il-forma tal-linja. (Obstacles include pins, copper foil, forbidden areas, holes and other objects) part of the circuit of two PCB models. Il-wajers ħodor u ħomor jimxu fuq saffi differenti tal-mudell tal-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. Il-Figura 1B hija mudell tal-PCB li tuża arki u angoli arbitrarji. 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. Turi PCB reali żviluppat fl-1972 minn kumpanija Amerikana msejħa Digibarn għal wajers tal-idejn kompluti. This is a PCB board based on Intel8008 computer. Il-wajers tal-Angolu arbitrarji murija fil-Figura 2 huma fil-fatt simili. Għalfejn jużaw wajers ta ‘Angolu arbitrarji? Minħabba li dan it-tip ta ‘wajers għandu ħafna vantaġġi. Arbitrary Angle wiring has many advantages. L-ewwelnett, jekk ma tużax l-angoli bejn is-segmenti tal-linja tiffranka l-ispazju tal-PCB (il-poligoni dejjem jieħdu aktar spazju mit-tanġenti). Traditional automatic cablers can place only three wires between adjacent components (see left and center in Figure 3). Madankollu, meta wajers fi kwalunkwe Angolu, hemm biżżejjed spazju biex tqiegħed 4 wajers fuq l-istess triq mingħajr ma tikser il-verifika tar-regola tad-disinn (DRC). Ejja ngħidu li għandna ċippa ta ‘modalità pożittiva u rridu ngħaqqdu l-pinnijiet taċ-chip ma’ żewġ pinnijiet oħra. Using only 90 degrees takes up a lot of space. L-użu ta ‘wajers ta’ Angolu arbitrarji jista ‘jqassar id-distanza bejn iċ-ċippa u pinnijiet oħra, filwaqt li tnaqqas il-footprint. In this case, the area was reduced from 30 square centimeters to 23 square centimeters. Rotating the chip at any Angle can also provide better results. 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. Din mhix biss teorija, iżda wkoll soluzzjoni prattika (xi kultant l-unika soluzzjoni possibbli). Shows an example of a simple PCB. Ir-riżultati tal-kejbil tat-topoloġija, filwaqt li r-riżultati tal-kejbil awtomatiku bbażati fuq forma ottimali huma ritratti tal-PCB attwali. An automatic cabler based on optimal shape cannot do this because the components are rotated at arbitrary angles. Għandek bżonn iktar erja, u jekk ma ddurx il-komponenti, l-apparat irid isir akbar. Layout performance would be greatly improved without parallel segments, which are often a source of crosstalk. 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. Jekk hemm Angolu bejn is-segmenti tal-wajer, allura hekk kif dan l-Angolu jiżdied, il-livell tal-krosstalk jonqos. 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. Ikkunsidra t-tliet metodi ta ‘wajers li ġejjin. 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. Il-kejbil awtomatikament jikkalkula l-għamla ottimali tal-wajer (b’kont meħud tal-ispazju ta ‘sigurtà meħtieġ). Kejbils flessibbli jistgħu għalhekk inaqqsu bil-kbir il-ħin meħtieġ biex teditja t-topoloġija, billi jappoġġjaw b’mod sabiħ reċipjenti multipli biex jissodisfaw ir-restrizzjonijiet. Dan juri disinn tal-PCB li jiċċaqlaq minn toqob u punti tal-fergħa. Matul il-moviment awtomatiku, il-punti tal-fergħa tal-wajer u t-toqob li jgħaddu huma aġġustati għall-aħjar pożizzjoni. 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. Meta tinstab triq, hija ffissata u ssir parti mill-labirint. L-iżvantaġġ tal-wajers sekwenzjali huwa li r-riżultat tal-wajers jista ‘jiddependi fuq l-ordni tal-wajers. Meta l-kwalità topoloġika għadha ‘l bogħod milli tkun perfetta, il-problema ta’ “teħel” isseħħ f’żoni lokalment żgħar. 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. Il-liwi tal-wajers jirreferi għall-fenomenu li wajer f’netwerk wieħed għandu jimxi madwar oġġett fuq netwerk ieħor biex ikollu aċċess għal oġġett. Rewiring a wire will not correct this. Eżempju ta ‘liwi huwa muri. A lit red wire travels around a pin in the other network, and an unlit red wire connects to this pin. Ir-riżultati tal-ipproċessar awtomatiku huma murija. 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. Wajers mgħawġa ħomor huma enfasizzati. F’siġra Steiner, il-linji kollha għandhom ikunu konnessi bħala segmenti ma ‘vertiċi (punti tat-tarf u żidiet). Fil-quċċata ta ‘kull vertiċi ġdid, tliet segmenti għandhom jikkonverġu u mhux aktar minn tliet segmenti għandhom jintemmu. The Angle between the line segments that converge to the vertex shall not be less than 120 degrees. Mhuwiex diffiċli ħafna li tibni Steiner b’dawn il-proprjetajiet kondizzjonali suffiċjenti, iżda mhux neċessarjament minimu. Gray Steiner trees are not optimal, but black Steiner trees are. Fid-disinn prattiku tal-komunikazzjoni, għandhom jiġu kkunsidrati tipi differenti ta ‘ostakli. Huma jillimitaw l-abbiltà li jinbnew siġar minimi li jkopru kemm bl-algoritmi kif ukoll siġar Steiner billi jużaw metodi ġeometriċi. 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. Il-mekkaniżmu ewlieni hawnhekk huwa algoritmu bbażat fuq il-forza li jikkalkula l-forzi li jaġixxu fuq il-punti l-ġodda u jċaqalquhom ripetutament għal punt ta ‘ekwilibriju (il-kobor u d-direzzjoni tal-forzi jiddependu fuq il-wajers fil-punti tal-fergħa li jmissu magħhom). Jekk l-Angolu bejn par ta ‘segmenti tal-linja konnessi ma’ vertiċi (terminus jew żieda) huwa inqas minn 120 grad, jista ‘jiżdied punt ta’ fergħa, u allura jista ‘jintuża algoritmu mekkaniku biex itejjeb il-pożizzjoni tal-vertiċi. 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. Jippermetti wkoll għal żoni fejn il-konnessjonijiet tal-endpoints huma pprojbiti, u n-numru ta ‘nodi tal-endpoints jista’ jkun arbitrarju.

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. Uħud mis-saffi fid-dijagramma ħarbu mill-wajers. Il-Figura 16 turi kwart ta ’BGA. Fl-istess ħin, meta tuża l-metodu tal-wajers “ċentru għal periferija”, in-numru ta ‘kanali meħtieġa biex joħorġu għall-periferija ma jinbidilx minn saff għal saff. Dan inaqqas ħafna n-numru ta ‘saffi. Għal daqs tal-komponent ta ’28x28mm, 7 saffi huma biżżejjed. Għal komponenti akbar, huwa 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. Kejbil awtomatiku topoloġiku ta ‘Angolu arbitrarju jista’ jagħmel dan. 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.