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I have a few questions about this PCB, namely the wires across the visible side:

enter image description here

  • I am new to electronics. Would these wires be considered a "trace", "jump", a "via", or something else entirely?

  • How would this be illustrated on a schematic to indicate that it is an actual wire and not part of the etching?

  • If one were to purchase this kind of solid wire, what would its gauge be, its material, and how would I search for it so that I exclude results with shielding?

  • Are there any issues with running wires like this without shielding? Such as electrical interference.

Other questions, not necessary for a complete answer:

  • Unless I am mistaken, these do not appear to be hand-made due do their exactness and how straight they are. How does a machine place these? Or are they pre-bent, placed, and then sent through a wave solder machine?

  • When would this method still used today? Or is it something that is an artifact of single-layer boards where one would otherwise use a through-hole via and traces on the other side?

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    \$\begingroup\$ @winny Please avoid answering questions comments. It serves no point what so ever other than to bypass the tools Stack Exchanges has put in place to ensure quality answers. \$\endgroup\$
    – pipe
    Commented Sep 15, 2018 at 9:31
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    \$\begingroup\$ @pipe: Good point. Mods really should clean up comments like that. Comments are only for building the question, or explaining to the OP what's wrong with it. I'll try flagging this comment and see how the mods react. Perhaps we should discuss this in meta. \$\endgroup\$
    – Olin Lathrop
    Commented Sep 15, 2018 at 12:58
  • \$\begingroup\$ @pipe: See the meta discussion electronics.meta.stackexchange.com/q/6728/4512. \$\endgroup\$
    – Olin Lathrop
    Commented Sep 15, 2018 at 13:26
  • \$\begingroup\$ If I just wanted a few jumpers like this, I'd use #22 or #24 solid hookup wire, and strip the insulation. \$\endgroup\$
    – Peter Bennett
    Commented Sep 15, 2018 at 16:14

2 Answers 2

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Would these wires be considered a "trace", "jump", a "via", or something else entirely?

Usually jumper wires or wire links.

How would this be illustrated on a schematic to indicate that it is an actual wire and not part of the etching?

They would not normally be shown on a schematic because they don't affect circuit operation and the use of the links is decided by the person who does the PCB layout. If, for some reason, they have to be shown on the schematic a 0 Ω resistor could be used.

If one were to purchase this kind of solid wire, what would its gauge be, its material, and how would I search for it so that I exclude results with shielding?

Gauge could be determined by PCB drill size for standardisation, bending equipment capability, current handling capacity, etc. Plated copper would be the normal choice for good conductivity and ability to solder.

Are there any issues with running wires like this without shielding? Such as electrical interference.

No. They're used here because the board is single sided. All the traces are unshielded.

Unless I am mistaken, these do not appear to be hand-made due do their exactness and how straight they are. How does a machine place these? Or are they pre-bent, placed, and then sent through a wave solder machine?

Given the few and odd components this board is most likely to be hand assembled.

enter image description here

Figure 1. An axial-lead component former would probably do the job. Source: OLAMEF USA.

When would this method still used today? Or is it something that is an artifact of single-layer boards where one would otherwise use a through-hole via and traces on the other side?

Yes, definitely, maybe, no. It depends. If it solves a particular routing problem, avoids an extra layer, etc., then why not.

enter image description here

Figure 2. Vishay make jumper wire taped in ammo fashion for ease of use in automatic insertion equipment. See Vishay WIRE0580000000A500 datasheet.

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  • \$\begingroup\$ This is an excellent answer! Also, thank you for the mention of the "axial-lead former". I didn't know that such a thing existed. \$\endgroup\$
    – Zhro
    Commented Sep 15, 2018 at 9:35
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    \$\begingroup\$ Have a look at the link supplied. There's a pile of interesting equipment for solving production problems. There's a surprising amount of manual work still done. The human hand and eye are extremely versatile and reprogrammable! \$\endgroup\$
    – Transistor
    Commented Sep 15, 2018 at 9:38
  • \$\begingroup\$ I found a great video of one of those machines forming leads at the necessary length (youtube.com/watch?v=uSPrCxD3aiM). Obviously machine-driven, most likely hand assembled. Amazing to see. \$\endgroup\$
    – Zhro
    Commented Sep 15, 2018 at 9:40
  • \$\begingroup\$ It's rather interesting that there's a market for bandoleered wire links rather than making them from a reel of wire. It means more standardised equipment for the PCB assembler so it must be worth the extra cost of having the wire come in that format. \$\endgroup\$
    – Transistor
    Commented Sep 15, 2018 at 11:25
  • \$\begingroup\$ Note that the PCB is assembled no earlier than late 2014, so definitely not a relic. \$\endgroup\$
    – pipe
    Commented Sep 15, 2018 at 11:48
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Yes, they are just by-pass wires to cross over one or more tracks of the printed layer. Yes, the are still used in simple, not very dense, and cheap circuits.

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