Sebastiaan FabAcademy

Week 6 Electronics Design

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In this week I had to focus on two things. Due to the limited time on the Shopbot ( assingment of week 7 ) in the fablab The Waag and in FabLabEnschede I had to work in advance to have my files ready by Thursday. It took all weekend to prepare the milling files ( see 3D printed parts and Tilt mechanisme ). So I focused this weeks assingment on the software program Eagle, with is also preferred by Emma. I followed the tutorial to make the first scheme. I have no experience what so ever with making and designing pcb boards. We had to make the Hallo Echo board. I didn't had so much trouble to make this layout of the Hallo Echo PCB layout.

In Eagle I switched over to the board. Some links where missing so I had to switch back to the schematic.

The problem was that some labels where wrongly typed. I correted it.

Back to the Board, again checking the layout if there are missing links. The links where ok so the components could be rearranged

The layout was made more compact

I tried Auto-routing and this layout was made

After finishing the upper layout, I added the LED, switch and resistor 499 ohm to the schematic

I also rearranged the schematic so that it became cleaner to look at.

Time to switch to the Board. I checked the links and all links where connected.

I clicked on Auto-routing. This was an terrible mistake. It took a while to understand that I had to get rid of the auto-routed lines and had to draw the lines my self. It was really irritating to try to change the Auto-routed lines.

I tried to change the Auto-routes lines but at this stage I stopped.

After a while of searching in the Eagle software I discoverd how I could draw the lines myself. This was the first result.

Some small adjustments where made.

Then I checked the gabs betweens the drawn lines if space between them is minimal 0.4 mm. This is the minimal distance because the smallest mill at The Waag is 0,4 mm. At my own Electronic Department At Saxion University of applied science it is 0,2 mm, but that I discoverd later when I went there to make my pcb. To make sure that the gabs between the lines where minimal 0.4 mm I had to do some line movements.

With DCR I did a check. I changed the position of the lines again until it was ok.

The parameter of the minimal mill diameter of 0,4 mm

I did again a check. I looked into each error and changed the error that seemed to me a problem.

Because of the great traveling distance between my home and The Waag in Amsterdam I went in At Saxion University of applied science, where I work, to the electronic department and asked if I could mill the board. This was no problem. The machine is an LPKF. It is an professional CNC milling machine. The machine has 10 mills in an internal mill library. The machine loads and unloads the mill it self. Also the height adjustments is done automaticly.

In Eagle the files is saved als .GTL file with the right layers active. This file is imported in the software of the machine.

The layout of the PCB in the software. I was not satified with the lower line and decided to change it in Eagle. The file was then saved again in Eagle and imported in the software of the milling machine.

The result is that the bottom connection line is now straight.

After appliing the machine settings the copper platted board was placed in the machine.

The pcb board was place in the software on the right position. I placed it so that a minimal amount of copper plated board was wasted. The blue thin cirkel is the milling positioning. With the milling positioning I was able to check if the board was placed ok.

As revered above, the milling machine is equiped with a 0,2 mm mill.

After milling the electronic lines free, the 1,0 mm mill was used to clear the board from the not used copper.

The result of the first milling proces. Now the outline must be milled

A 2 mm outline mill was used to cut the PCB board free. The tabs are aded by the software it self.

The result in detail

After cutting the pcb free from the big board I cleaned the pcb. After this the soldering proces could start. I used special flux to improve the soldering proces.

The flux pencil

I startet with the microprocessor

A small mistake happened and had to be fixed to make the connection of the two pins separate.

The switch and connector where added.

The LED, 20 ghz clock and 10KOhm where added

A capacitor, resistor and and 8 pin connector added

Final result of this week

Circuit board