PCB wiring methods continue to improve, and flexible wiring techniques can reduce wire length and free up more PCB space. Conventional PCB wiring is limited by fixed wire coordinates and the lack of arbitrarily angled wires. Removing these limitations can significantly improve the quality of wiring.

Let’s start with some terminology. Gihubit namon ang arbitraryong Angle nga mga kable ingon mga wire wire nga gigamit ang dili arbitraryong mga Angle segment ug radian. Kini usa ka klase nga wire wire, apan dili limitado sa paggamit sa 90 degree ug 45 degree Angle segment nga linya. 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. Gipasabut namon ang termino nga dali nga pagkabutang nga mga kable ingon mga wire wire nga wala gitakda nga porma nga makahimo sa pag-isip sa tinuod nga oras nga porma sa wire aron makuha ang mosunud nga mga posibilidad sa pagbag-o. Ang mga arko ra gikan sa mga babag ug ang ilang kasagarang mga tangente ang gigamit aron maporma ang porma sa linya. (Obstacles include pins, copper foil, forbidden areas, holes and other objects) part of the circuit of two PCB models. Ang berde ug pula nga mga wire nagdagan sa lainlaing mga sapaw sa modelo sa 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. Ang numero 1B usa ka modelo sa PCB nga naggamit mga arko ug dili tinuyo nga mga anggulo. 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. Shows a real PCB developed in 1972 by an American company called Digibarn for complete hand wiring. This is a PCB board based on Intel8008 computer. Ang arbitraryong mga Angle nga kable nga gipakita sa Larawan 2 sa tinuud managsama. Why would they use arbitrary Angle wiring? Tungod kay kini nga klase sa mga kable adunay daghang mga bentaha. 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). Bisan pa, kung ang mga kable sa bisan unsang Angle, adunay igo nga wanang aron mahigda ang 4 ka mga wire sa parehas nga agianan nga wala maglapas sa pagsusi sa lagda sa disenyo (DRC). Pananglit adunay kami positibo nga mode chip ug gusto nga ikonektar ang mga chip pin sa duha pa nga mga pin. Using only 90 degrees takes up a lot of space. Ang paggamit sa arbitraryong Angle wiring mahimong makapamubo sa distansya taliwala sa chip ug uban pang mga lagdok, samtang gipamub-an ang tunob sa tiil. 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. Dili ra kini teyorya, apan us aka praktikal nga solusyon (usahay ang posible nga solusyon). Shows an example of a simple PCB. Topology cabler results, while automatic cabler results based on optimal shape are photos of the actual PCB. An automatic cabler based on optimal shape cannot do this because the components are rotated at arbitrary angles. Kinahanglan nimo ang daghang lugar, ug kung dili nimo pagtuyokon ang mga sangkap, ang aparato kinahanglan himuon nga labi ka daghan. 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. Kung adunay usa ka Angle taliwala sa mga bahin sa wire, kung ingon niini nga pagtaas sa Angle, maminusan ang lebel sa crosstalk. 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. The cabler automatically calculates the optimal shape of the wire (taking into account the necessary safety clearance). Flexible cabling can therefore greatly reduce the time required to edit the topology, nicely supporting multiple recabling to meet constraints. Nagpakita kini usa ka laraw sa PCB nga moagi sa mga lungag ug mga puntos sa sanga. During automatic movement, wire branch points and through-holes are adjusted to the optimal position. 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. Kung nakit-an ang usa ka agianan, kini naayo ug nahimo nga bahin sa maze. The disadvantage of sequential wiring is that the wiring result may depend on the wiring order. Kung ang kalidad sa topological layo pa sa kahingpitan, ang problema sa “pag-ali” mahitabo sa mga gamay nga lugar. 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. Ang wire lending nagtumong sa panghitabo nga ang usa ka wire sa usa ka network kinahanglan nga maglakaw libot sa usa ka butang sa lain nga network aron ma-access ang usa ka butang. Rewiring a wire will not correct this. Usa ka pananglitan sa pagyukbo gipakita. A lit red wire travels around a pin in the other network, and an unlit red wire connects to this pin. Gipakita ang mga sangputanan nga awtomatikong pagproseso. 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 bent wires are highlighted. In a Steiner tree, all lines must be connected as segments to vertices (endpoints and additions). At the top of each new vertex, three segments must converge and no more than three segments must end. The Angle between the line segments that converge to the vertex shall not be less than 120 degrees. It is not very difficult to construct a Steiner with these sufficient conditional properties, but it is not necessarily minimal. Gray Steiner trees are not optimal, but black Steiner trees are. Sa praktikal nga laraw sa komunikasyon, kinahanglan hunahunaa ang lainlaing mga lahi. They limit the ability to construct minimum spanning trees using both algorithms and Steiner trees using geometric methods. 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. Ang nag-unang mekanismo dinhi usa ka algorithm nga nakabase sa puwersa nga nagkwenta sa mga pwersa nga naglihok sa bag-ong mga taludtod ug balikbalik nga gibalhin kini sa usa ka punto nga katimbangan (ang kadako ug direksyon sa mga pwersa nagsalig sa mga alambre sa kasikbit nga mga punto sa sanga). Kung ang Angle taliwala sa usa ka pares nga linya sa linya nga konektado sa usa ka vertex (terminus o pagdugang) dili moubos sa 120 degree, mahimo nga madugang ang usa ka point point, ug pagkahuman mahimo gamiton ang usa ka mechanical algorithm aron ma-optimize ang posisyon sa 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. It also allows for areas where endpoint connections are prohibited, and the number of endpoint nodes can be arbitrary.

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. Figure 16 shows a quarter of a 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. This will greatly reduce the number of layers. For a component size of 28x28mm, 7 layers are sufficient. For larger components, it’s a 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. Arbitrary Angle topological automatic cabler can do this. 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.