History

If you open any electronics equipment, you can see that all the components are mounted on a board where are drawn all the tracks to connect the components pins.
This board, to be realized, need a "Master" or Printed Circuit Board Layout.
The Printed Circuit Board Layout is composed by some sheet and afterwards by some film, where is represented the track layout, needed to carry out all the connection between the components needed to realize any electronic circuit.
Using this films, we obtained the real PCB, composed by an insulated base, "vetronite" (FR4), "bachelite" or similar, where has been glued a thin sheet of copper.
Using a photoengraving process, the unnecessary copper is eliminated and on the PCB remain all the needed tracks for the connections. Other films are needed to realize the Solder Mask that is a thin paint layer needed to protect the tracks where soldering is not needed, from oxidation and dust.

1977
In 1977 the Personal Computer were non-existent as well as the Programs needed to realize a Printed Circuit Board Layout or "Master" so all the work to make it was hand-made.
The first Masters made by Tecno77 were made using a support called "Ulano". The Ulano is a transparent film on which was applied a thin colored layer that is removable.
First, on a sheet, you had to draw by hand the tracks layout and the components dimension, starting from the schematic layout.


Schema Elettrico

Electrical Layout Designed by Hand.


On a backlighted table was applied a Sheet of Ulano over the Tracks Layout and then began the real work removing all the part unnecessary, obtaining at last one layer.
Fortunately the first Master were often a single layer...



Master Ulano

Examples of Master made with Ulano


With a cutting compass and precision cutters, the part not needed was removed obtaining a negative image of the layer to be realized.
Obviously, having to make a double-sided circuit, all the work was repeated for the second layer and than there were the Solder Layer, the Silkscreen etc..

1980
The work was somewhat simplified with the advent of the Adhesive Transfer Tape and sheet of Dry-Transfer Pads.
Always usign a Reference Sheet, on which were traced the tracks taking into account the insulation and the dimensions of the components, began the task of copy using the Dry-Transfer Pads and the Adhesive Tape.

 

Tracciato Piste

Example of Tracks Layout


On a sheet of acetate, helped by a backlighted table on wich was applied a graduated sheet, were first applied the Dry-Transfer Pads and then the connections were achieved through the application of Adhesive Tape.
Even in this case, however, the layer were to be implemented one by one.

 

Nastrini

At work with the Adhesive Transfer Tape


1984
In this period began to be available the first Home Computer made by IBM and the first programs to implement the master.

 

Foto Storica

Historical photos of Tecno77 with the first PC and PCB Programs


The programs were very expensive and so were the first Computers, but there was a great advantage in achieving Master for Printed Circuit Board with the help of a Program on your computer.
Once completed the work, all the faces were made without having to start over again to draw the Pads for the second layer, for the Solder Mask, then the tracks etc.
At the end of the routing and verified the errors, the files generated by the program were sent to a pen plotter that printed in scale 1:1 or 2:1 the "film".
After a few years, with the advent of the photoplotter laser, was achieved a significant improvement of the work, both in terms of speed than in the accuracy.
With the photoplotter laser, in fact, were obtained directly the films used in the production process through photoengraving.

Today
Increased complexity, speed signal, number of components and reduced physical dimensions of the components, make it impossible today the creation of master made "By-Hand", without the aid of dedicated computer programs, useful to take into account the insulation, the size and length of tracks, etc.
The work of the "Master Designer" is always a manual work, but any aid coming from dedicated programs to simplify the work itself is welcome so the Master Designer can focus more on the desired result, namely to obtain a card good and running and, why not, also "nice" to be seen aesthetically.

 

Foto di una stazione di sbroglio attuale

And how things look today