Printed Circuit Boards
There are many ways to assemble this matrix: I decide to do this using a printed circuit board, but divided into four sections for easier handling. The following shows the construction process:
PCB and component layout.
PCB layout printed on a paper sheet transparent to UV light.
Cooper board are marked for cutting to the correct size.
They are labeled and a corner is cut off so that they fit on the chessboard.
The four boards will be placed on the chessboard in this way.
I coat all the copper with photosensitive lacquer.
This process has to be done with very low light.
3 min of "daylight" to sensitize the areas not protected by the photolithography.
I use a Philips Photolita-S 250W lamp.
The board is developed in a solution of sodium hydroxide. This is a "positive" development.
The result of developing is a board with the tracks drawn with lacquer.
Now the board is immersed in ferric chloride. This acid eats the copper from those areas without the lacquer coat.
After rinsing with water and drying, we already have a PCB.
The other three are made, and the lacquer is removed with acetone.
Now the holes are drilled.
And we have finished the four PCBs.