PCB metotia faʻaauau faʻaauau pea ona faʻaleleia, ma fetuʻutuʻunaʻi metotia faʻavaea mafai ona faʻaititia le uea umi ma leai se tele avanoa PCB. E faʻatapulaʻaina fesoʻotaʻiga PCB masani e ala i le faʻamaopoopoina o uaea ma le le lava o uaea feʻaveaʻi faʻatasi. O le aveʻesea o nei mea faʻatapulaʻa mafai ona faʻaleleia atili ai le tulaga o uaea.

Let’s start with some terminology. Matou te faʻamatalaina le faʻaopoopoina o le faʻaogaina o laina uaea e pei o uaea uaea e faʻaaogaina ai vaega o le tulimanu e le faʻatonuina ma radians. O se ituaiga o uaea uaea, ae le gata ile faʻaaogaina naʻo le 90 tikeri ma le 45 tikeri Angle laina laina. 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. Seʻi o tatou faʻauiga le faaupuga fetuʻutuʻunaʻi uaea pei o uaea uaea e aunoa ma se faʻamau foliga e mafai ai ona moni-taimi uaea foliga toe faʻatulagaina e ausia ai nei suiga suiga. Naʻo arcs mai faʻafitauli ma latou masani faʻamau e faʻaaogaina le laina foliga. (Obstacles include pins, copper foil, forbidden areas, holes and other objects) part of the circuit of two PCB models. O ua lanumeamata ma mumu uaea o loʻo tamoʻe luga o vaega eseese o le PCB faʻatusa. 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. Ata 1B o se PCB faʻataʻitaʻiga faʻaaogaina arcs ma faʻatatau vaʻai. 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. Faʻaalia se PCB moni na atiaʻe i le 1972 e se kamupani Amerika ua faʻaigoaina o le Digibarn mo faʻamaea atoatoa lima. This is a PCB board based on Intel8008 computer. O le le faʻatonuina Angle wiring faʻaalia i le Ata 2 e tutusa tutusa. Why would they use arbitrary Angle wiring? Aua o lenei ituaiga o uaea e tele lelei. Arbitrary Angle wiring has many advantages. First, not using the angles between line segments saves PCB space (polygons always take up more space than tangents). Traditional automatic cablers can place only three wires between adjacent components (see left and center in Figure 3). Peitaʻi, a oʻo i se uaea le uaea, e lava le avanoa e faʻataʻi ai uaea e 4 i luga o le auala e tasi e aunoa ma le solia o le tulafono o loʻo siakiina (DRC). Faapea o loʻo ia i tatou se auala lelei faʻamau ma manaʻo e faʻafesoʻotaʻi ia matasini pin i isi lua pine. Using only 90 degrees takes up a lot of space. O le faʻaaogaina tatau ole Angle wiring e mafai ai ona faʻapuʻupuʻu le va i le va o le chips ma isi pine, ae faʻaititia le tulagavae. 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. Lenei e le gata o se teori, ae o se faʻatinoina tali (o nisi taimi na o le mafai vaifofo). Shows an example of a simple PCB. Topology cabler iʻuga, ae otometi cabler iʻuga faʻavae i luga o sili ona lelei foliga o ata o le moni PCB. An automatic cabler based on optimal shape cannot do this because the components are rotated at arbitrary angles. E te manaʻomia ni vaega se tele, ma afai e te le mimiloina vaega, e tatau ona faʻateleina le masini. 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. Afai e i ai se Angle i le va o uaea vaega, lea a faʻateleina lenei Angle, o le maualuga o le crosstalk o le a faʻaititia. 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. Consider the following three wiring methods. 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. O le cabler otometi lava fuafua le sili ona lelei foliga o le uaea (i le amanaʻia o le kilia talafeagai saogalemu). Fetuunaʻiina cabling mafai ona sili faʻaititia le taimi manaʻomia e faʻasaʻo le topology, lelei lagolagoina le tele o toe faʻafetaui e faʻafetaiaʻi tapulaʻa. Lenei faʻaalia ai se PCB mamanu e minoi i pu ma lala lala. I taimi o gaioiga otometi, uaea lala lala ma ala-pu e fetuʻunaʻi i le tulaga sili ona lelei. 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. A maua se ala, e faʻasaʻo ma avea ma vaega o le paso. O le le lelei o faʻasologa faʻapipiʻi o le iʻuga iʻuga ono faʻamoemoe i luga o le faʻasologa faʻatonu. Afai o le topological tulaga lelei o loʻo mamao mai le atoatoa, o le faʻafitauli o le “pipii” e tupu i totonu o eria laiti eria. 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. O le loloʻuina o uaea e faʻasino i le mea mataʻutia e tatau ona savali faataamilo se uaea i le tasi upega i se mea i luga o seisi upega e ulufale ai i se mea. Rewiring a wire will not correct this. O loʻo faʻaalia se faʻataʻitaʻiga ole punou. A lit red wire travels around a pin in the other network, and an unlit red wire connects to this pin. Ua faʻaalia iʻuga otometi. 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. Ua faʻamamafaina uaea piʻo mumu. I totonu o le Steiner tree, o laina uma e tatau ona fesoʻotaʻi o ni vaega i pito i luga (faʻaiʻuga ma faʻaopoopoga). I le pito i luga o vertex fou taʻitasi, e tolu vaega e tatau ona faʻatasia ma e le sili atu i le tolu vaega e tatau ona faʻamutaina. The Angle between the line segments that converge to the vertex shall not be less than 120 degrees. E le faigata tele ona fausia se Steiner ma nei lava tuʻutuʻuga meatotino, ae e le tatau ona laʻititi. Gray Steiner trees are not optimal, but black Steiner trees are. I le aoga faʻatulagaina fesoʻotaʻiga, eseʻese ituaiga o faʻafitauli e tatau ona mafaufauina. Latou te faʻatapulaʻaina le mafai ona fausia ni laʻititi faʻalauteleina laʻau faʻaaogaina uma algorithms ma Steiner laau faʻaaogaina metotia geometric. 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. O le autu auala iinei o se malosi-faʻavae algorithm e fuafua ai le malosiʻaga faia i luga o le vaʻa fou ma faʻasolosolo faʻaseʻeina i latou i se tulaga paleni (o le maualuga ma le faʻatonuga o malosiʻaga faʻamoemoeina i uaea i tuaoi lala lala). Afai o le Angle i le va o se pea o laina laina fesoʻotaʻi i le vertex (terminus po o le faʻaopopoga) e itiiti ifo i le 120 tikeri, e mafai ona faʻaopopoina se lala lala, ona mafai ai lea ona faʻaaogaina se masini algorithm e faʻalelei ai le tulaga vertex. 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. E faʻatagaina foi mo eria e faʻasaina ai fesoʻotaʻiga, ma o le numera o pito i luga e mafai ona faʻatulafonoina.

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. Some of the layers in the diagram have escaped wiring. Ata 16 o loʻo faʻaalia ai le kuata o le BGA. At the same time, when using the “center to periphery” wiring method, the number of channels required to exit to the periphery does not change from layer to layer. Lenei o le a matua faʻaititia ai le numera o faaputuga. Mo le vaega tele o 28x28mm, 7 faaputuga ua lava. Mo vaega tetele, o se manumalo-malo. 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. Arbitrary Angle topological otometi cabler mafai ona faia lenei. 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.