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| Built at: Sept.22.2001 Last update: Dezember 06, 2004 |
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Diese Seite ist auch in Deutsch verfügbar |
Now I have published some electronic circuits for KAP, so that I want to describe the making of an electronic circuit bord for example on the elektronic switch01 here.
| The electronic switch01: The circuit bord of the electronic switch01 is only sized 25 x 38 mm. The components are put through the drillings from above and soldered whith the wires on the underside. |
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Attention! Safety-advice:
The safety informations from the
manufacturer must be read first.
To protect yourself you must use safety goggles, rubber-gloves,
and a rubber apron.
 1,5mm sourche material from Bungard |
The source material: To get a small and light pcb it must be produced with the photo technic. The source material is a fiberglass board. On this board there is a 35 um thin layer from copper. This layer is acid protectet by a second layer. This protection layer is sensitive to UV-light and protected by a film. |
| Pcb film: The wires must be transfered with an optical method to the pcb. At first there must be a layout-foil. You have to printout the layout and reduce it to the right size with a copymashine (see 25 mm. I write it on every layout). Now you have a little sharp layoutfoil. It is mirrored so that the layerside comes to the top of the circuit board. This reduces an underlight at the exposing and the ready circuit board is very sharp. On the finished pcb the text must be readable normal! |
 Printout and resized pcb-film |
 The pbc-foil mirrored on the glass-sheet. |
Expose: With this layout-foil you can expose the circuit board. It is important that there is no distance between the film and the source material. Otherwise the light can reach the UV-protection layer from the side and the wires become blurred or interrupted. |
| Now the pcb-board can be exposed with UV-Light. The exposetime ist different to the lightsourche and the distance between the light and the circuit-board. You have to experiment with some little pieces. A good lamp is the Philips TLD 15W (see picture). I use an exposetime from 90 up to 120 sec. |  Exposing with speziell UV-Lamps |
Attention! Safety-advice:
The safety informations from the
manufacturer must be read first.
To protect yourself you must use safety goggles, rubber-gloves,
and a rubber apron.
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Developing: The exposed protection layer is destroyed by the UV-light. With a developer it can be removed from the copper-layer now. You have to put the board into a dish with the developer and move it up and down slowly. After a short time you can see that the exposed UV-protection layer will be removed from the board and the copper lays open. Wash up the board after developing. |
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After the developing you get a fiberglass board with a copper-layer. This copper is protected at some places by the protection layer. At this protected places the wires will result in the next step. At that places, where the UV-light has reached the protection-layer it is destroyed and the copper in unprotected now. |
Attention! Safety-advice:
The safety informations from the
manufacturer must be read first.
To protect yourself you must use safety goggles, rubber-gloves,
and a rubber apron.
| Etching: Now the board can be etched. The unprotected copper-area is removed and the protected areas become the wires. |
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 The pcb-board from the electronic-switch01b . |
After some minutes the pcb-board ist finished and must be washed proper. Now the chemical process is finished and the mechanical work follows. |
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Drilling: The finished circuit board must be drilled with a small drill (0,8 mm). You have to use a standdrillingmachine ore a minimachine with a spechial holder. In the middle of the solderpads there is a small hole so that the drill will get the center by itself. After that a few drillings must be drilled with a bigger diameter. For example the mounting drills. |
| Filing and finishing: The ready drilled board must be filed to the right measurings now. |
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Washing: There is a rest from the protection-layer at the board on both sides. It can be removed with alcohol (spirit). |
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| Mounting: After the mechanical work is done you have to add the components to the circuit board and solder them at the solder-side. Low price parts I solder direct onto the board. Microcontrollers should be plugged in an IC-socket because the programm must be canged at some time. Some parts must be placed in the right direction. So always look at the mountingplan. |
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Links to other KAPers and more you can find in my Surfers Guide.
I like to be available for questions, suggestions or experience exchange.
I would be very pleased about an entry in my visitor's book.
Manfred
http://KAP-Man.de
Manfred