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Week 8. Group / Electronics Production

This is group assignment page for West harima student :

Student

group assignment

  • characterize the design rules for your in-house PCB production process
  • submit a PCB design to a board house

machine

Roland MODERA model MDX-40 (Update to MDX-40A)

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machine spec Description
Cuttable material Resins such as chemical wood and modeling wax (metal not sup- ported)
Work area 305 (x) x 305 (y) x 105 (z) mm
Workpiece table size Width x depth: 305 × 305 mm
Loadable workpiece weight 4kg
Operating speed XY axis: 7 to 3000 mm/min.
Z axis: 7 to 1800 mm/min.
Spindle Motor DC brushless motor, max 100W
Spindle rotation 4,500 to 15,000 rpm
Overall Machine Size 669 x 760 x 554 mm
Machine Weight 66kg
Software resolution 0.01mm/step (RML-1)
0.001mm/step (NC code)
Control command sets RML-1, NC code
Computer Model preinstalled with Windows 7, Vista (32/64-bit edition) or XP, or upgraded computer originally preinstalled with Windows XP or later

Manual

Software

  • I use VPanel for MDX-40A

Material

I use FR1 (Paper phenol), one side

  • Size: 100 x 150 x 1.6(t) mm
  • Cu thickness: 35um = 0.035mm

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Endmill

I use below Endmill.

End mill Where to buy Maker : model number
Interior (Board outline) Diameter 0.8 mm
(number of flutes: 2)		 MISUMI OSG: WXL-2D-DE-0.8
Trace Diameter 0.4 mm
(number of flutes: 2)		 MISUMI OSG: WXL-2D-DE-0.4

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今回私は FabLab West-harim で使用されているものと同じものを購入しました。

  • data sheet (OSG WXL-2D-DE)

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Although the values listed in the data sheet are preferred, they are too time-consuming, so values based on FabLab West-harim’s experience were used.

MODS

In this time, I use MODS to create tool path for test cut trace and save file, using MDX-40A.

terminology
tool diameter End mill diameter
cut depth Depth of cut in one pass
max depth Final depth of cut
offset number Amount of offset to be cut from the periphery of the pattern
stepover Overlap of endmill when cutting

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  • open the MODS

  • Right click > Programs > Open program > Roland MDX mill “PCB”

1.Select png file of Trace, and choose dpi(2000)

2.Set tool diameter(0.4mm), cut depth(0.15mm), max depth(0.3mm)

3.select machine(MDX-40), cut speed(2.5　mm/s), jog Z(2.5 mm), origin(x0,y0)

4.select save file

5.calculate

Then, I could get the tool path for the test cut.

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  • Calculate generates a path like this alt text

PCB design rule and milling test

  • We did not have clear PCB design rule. Then we set as below based on tutor’s advice.

    • Pattern line width

      • Power line 0.8mm, signal line 0.4mm
      • Gap 1.2d

    • Edge cut: Use 0.8mm mill

  • For confirming our milling machine [Roland DX-40]’s performance, we made test data as below. Both pattern and gap start from 0.1mm to 1mm with 0.05mm steps. This data was provided by the instructor.

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NOTE: When I initially tried to reflect this data in MODS and calculate it, the data couldn’t be loaded properly.
I changed the line color to white and the background color to black and it loaded fine. I wonder if it’s easier to distinguish that way…

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Cutting conditions
cutting speed 150mm/min
end mill diameter 0.4mm
Cut depth 0.15mm

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  • I use 0.4mm diameter end mill. This is why the gap under 0.4mm was not possible.
  • On the other hand, even 0.1mm line well milled.

Board House

I used the original board that was created in Week8. I simulated the order right up to the moment before placing the order. Board House used PCBGOGO.

Gerber data

GerBer data is one of the data file formats used in manufacturing printed circuit boards.

  • Set the origin of the drill position

place > drill/place file origin

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Click where you want to set the origin (lower left corner of the board)

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  • Output Gerber Data

File > Fabrication Outputs > Gerbers(.grb)

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  • Set the output destination for Gerber data

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  • Select a layer

I made sure that all the LAYERS I am using are checked.

  • Set general options

Check the “Use drill/placement file origin” checkbox in the General Options.

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  • Set Gerber Options

  • Execute the plot

When settings are complete, click the Plot button.

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Gerber files are output in the format of “File name + Layer name.

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  • Check Gerber data

Select Gerber Viewer from KiCad’s main menu.

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  • Open a Gerber job file

File > Open Gerber jobFile

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Each layer is displayed as follows

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PCBGOGO

I registered an account and tried.

  • Enter PCB Instant Quote

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  • Set manufacturing conditions

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my settings
Material Normal FR-4 Board
Different Design in Panel 1
Size 67 x 67 mm
Quantity 5
panel Way Single piece
Layers 1 Layer
FR4-TG TG 150
Thickness 1.6
Min Track/Spacing 6/6 mil
Min Hole Size 0.3 mm
Solder Mask White
Silkscreen Black
Gold Fingers Yes (Bevelling = Yes(30),Hard Gold)
Au/Ni thickness Au:10U”/Ni:120U”
Surface Finish Immersion gold(ENIG)
Thickness of Immersion Gold 1U”
Via Process Tenting vias
Finished Copper 1 oz. Cu
PCB Assembly No
SMD-stencil No

NOTE :
Min Track/Spacing The unit of the “1” is “mil”. mil is 1/1000 inch, so it is 0.0254 mm when converted to mm units. 5 choices converted to mm are shown below.

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  • Calculate

Data file

Impressions　and What’s I learned

  • Lines smaller than the diameter of the endmill cannot be milled.
  • I found that it takes a lot of settings before milling, which made it difficult.
  • I learned that it takes more time than expected to place an order at the Board House.