[SeniorSitizen]

This circuit board on a old telephone, from around 1905, is the earliest I've found. I wonder what it was actually named then.

 

[TimPa]

are the lines that are showing the circuit conductors/lands?

i'll bet the term circuit board was more applicable then that it is on todays circuit boards.

 

[123pugsy]

This circuit board on a old telephone, from around 1905, is the earliest I've found. I wonder what it was actually named then.

I thought the same thing when I was rebuilding my Kellogg phone.

 

[SeniorSitizen]

are the lines that are showing the circuit conductors/lands?

i'll bet the term circuit board was more applicable then that it is on todays circuit boards.

You probably correct about the board.

There are wires in the grooves that lead to their respective components inside the case via holes at their groove ends.

 

[AllanJ]

Today's circuit boards were originally called printed circuits or printed circuit boards. They started as a fiber or fiberglass or similar board with a thin layer of copper on one side. Using thin strips of tape or using painting or printing processes, lines corresponding to the circuit traces or circuit conductors were placed on the copper surface. Then the board was dipped in acid to eat away the uncovered copper leaving just the circuit traces.

The grooves in the circuit board pictured above were to protect the wires from physical damage since the board is the rear of the telephone unit that was attached to a wall. Unlike the copper traces on a (single layer) printed circuit board, the grooves could be engraved at different depths so wires could cross over each other.