Show HN: Copperhead – Cursor for circuit boards

Post by Joel_Mckay » Tue, Sep 08, 2026, 5:52 PM UTC

monocasa wrote: post #59

Joel_Mckay wrote: post #39

Earlier quoted context omitted.

Every trace on a PCB is a traveling salesman problem with ballooning complexity. https://en.wikipedia.org/wiki/Travelling_salesman_problem While physics informed models do exist, they are still going to burn a lot of compute to generate failure modes people didn't know were possible. =3 https://www.youtube.com/watch?v=T4Upf_B9RLQ

Well, no, it's not. If anything, it's closer to the bin packing problem. The cost function isn't expressed in terms of lowest cost between nodes, but instead fitting all of the traces with the lowest board layer count while still meeting stuff like EMI crosstalk guidelines. Then there'll be some traces that are very constrained (think DRAM or SERDES links) that have to be length matched, but those are pretty much inv…

Post by monocasa » Tue, Sep 08, 2026, 5:57 PM UTC

Joel_Mckay wrote: post #61

monocasa wrote: post #59

Earlier quoted context omitted.

Well, no, it's not. If anything, it's closer to the bin packing problem. The cost function isn't expressed in terms of lowest cost between nodes, but instead fitting all of the traces with the lowest board layer count while still meeting stuff like EMI crosstalk guidelines. Then there'll be some traces that are very constrained (think DRAM or SERDES links) that have to be length matched, but those are pretty much inv…

>Traces being, say 20% longer than they need to be doesn't really change the performance of the board Impedance matching requires you know what you are doing, and Altium will only take you so far. For the price, Altium/Protel has always been a poor deal for what you get software wise. Even free Qspice (a more modern Analog Devices LTSpice) is a far better option: https://www.qorvo.com/design-hub/calculators-simulatio…

Post by Joel_Mckay » Tue, Sep 08, 2026, 6:16 PM UTC

monocasa wrote: post #63

Joel_Mckay wrote: post #61

Earlier quoted context omitted.

>Traces being, say 20% longer than they need to be doesn't really change the performance of the board Impedance matching requires you know what you are doing, and Altium will only take you so far. For the price, Altium/Protel has always been a poor deal for what you get software wise. Even free Qspice (a more modern Analog Devices LTSpice) is a far better option: https://www.qorvo.com/design-hub/calculators-simulatio…

> Impedance matching requires you know what you are doing, and Altium will only take you so far. For the price, Altium/Protel has always been a poor deal for what you get software wise. Pretty much every high end board is designed under Altium. QSpice is a different tool for a different purpose. And like I said, those few cases were the length actually matters tend to be heavily assisted with automation as it is. > I…

Post by monocasa » Tue, Sep 08, 2026, 6:56 PM UTC

Joel_Mckay wrote: post #65

monocasa wrote: post #63

Earlier quoted context omitted.

> Impedance matching requires you know what you are doing, and Altium will only take you so far. For the price, Altium/Protel has always been a poor deal for what you get software wise. Pretty much every high end board is designed under Altium. QSpice is a different tool for a different purpose. And like I said, those few cases were the length actually matters tend to be heavily assisted with automation as it is. > I…

>I guarantee you that an iPhone board isn't an optimal solution, DFM almost certainly guarantees an iPhone is both form, and cost optimized. Jobs was very clear early on in the product development that the EE work had to be miniaturized due to the energy density possible setting volumetric minimums on the battery technology at that time. > simply good enough. A common philosophy for people that make cost optimized lo…

Post by KingMachiavelli » Tue, Sep 08, 2026, 7:09 PM UTC

Joel_Mckay wrote: post #64

monocasa wrote: post #60

Earlier quoted context omitted.

So, then how are today's pcb layout techs solving these Np-hard problems in your mind, armed only with Altium?

Only decades of standards compliance, workmanship training, and experience. Human beings are very good at spotting patterns in noisy jungles, and making rational design tradeoffs. Auto-routers have been around far longer than even smartphones. Somewhat functional in the trivial problem domains, and always useless where design choices mattered. Best of luck solving a named problem. =3