Solderpaste Stencil

Stencil photo

You can make a solderpaste stencil using either the Protolaser or the Protomat mill, however we recommend that you use the Protolaser because it generally produces better results. If for some reason you cannot use the Protolaser, you can find the Protomat mill solderpaste stencil guide here.

Starting up the machine

Step 1:

Start by finding the LPKF ProtoLaser machine. Press the blue power button under the red E-stop button. This will power on the computer connected to the laser.

Step 2:

Find the software labeled "LPKF CircuitPro PL 3.5" on the desktop. Open the software and wait for it to boot up.

Step 3:

Check that all three signal lights are on. If they all are, select "Yes" when the software boots up.

Step 4:

The machine will go through the system connection. This should only take a second.

Prepping the File

Step 1:

The software will show various LPKF templates under the "New" tab.

Scroll down and double click "DCI Lab Polyimide Stencil Top" or "DCI Lab Polyimide Stencil Bottom" from My templates depending on which you need.

Step 2:

Under the "Material" tab, select the correct material used for the stencil. Select the Single-sided dropdown change to Foil. Then double click DCI Lab Polyimide Stencil for the material.

Step 3:

Before completing the following steps, skip to the Processing tab and select the red "Open laser shutter" button. This will start the warm up while you are setting up your file.

Step 4:

Return to the "Import" tab and click the green plus icon to add new files. Here you will choose the gerber file used to print the stencil.

Step 5:

Select either the "solderpaste_top.gbr" file or "solderpaste_bottom.gbr" depending on which template you used. Click the file and press "Open".

Step 6:

If you have a SolderPasteTop file, it will show as purple. A SolderPasteBottom file will show as blue.

Then select the Import button.

Step 7:

You should now see your stencil design on the layout. In this tab, you can rotate your design or make small edits. Typically, we do not do anything in this tab.

Step 8:

Head over to the "Scan fields" tab. Here you will need to compute scan fields. Do this by clicking the "Compute scan fields" button.

Step 9:

Typically we do not need to make any changes to the compute scan fields menu, so we will just select Compute.

A scan field is the area the laser beam can reach just using the mirrors without needing to move the entire bed.

Step 10:

Our stencil design is relatively small, so only 1 scan field was computed. If your board is bigger, more scan fields will be computed by the software.

Step 11:

Typically we should not have to make any edits to the Tools or Workflow paths and we will skip to the Toolpaths tab and select Compute toolpaths.

The software will compute the results. Click "Close".

Step 12:

You should see a single yellow line going around your purple shapes. This indicates where the laser will cut.

Step 13:

Now click the "Processing" tab. You should see your stencil toolpath on the board.

Preparing the material

Step 1:

Place the polyimide material over the white underlayment sheet and tape down the edges.

If it is a small piece of material you will need to cover most of the white sheet in tape so that the vacuum table can effectively hold down the polyimide sheet. If you don't, you may get an error about vacuum power.

Step 2:

In the Processing tab, right click the stencil and press "Placement". You will be able to move your board around to your desired location.

Step 3:

Using the laser, you will be able to see where you place your stencil. Double click a spot on the canvas to move the red cross-hair. This will move the laser to that location.

The red cross-hair is on the bottom left of the canvas, right above the newly-placed stencil.

Step 4:

Here is the laser moved to that location. You can see the small dot in the middle of the large surrounding circle that shows the laser. Use this laser to properly place your board.

Cut your Stencil

Step 1:

When properly placed and checked all the parameters, press "Start production" to start the laser process!

Step 2:

The material should already be taped onto the white sheet. Double check and once ready, select OK.

Step 3:

If you choose to place your board again, you will be able to here.

The "Material thickness" should be already set to 0.11mm. If you are using a different material than the one provided, make sure to measure the thickness.

Click "OK" to start the process.

Step 4:

The laser may need to warm up again. The stencil design will now be cut!

Step 5:

Cut out your new stencil using scissors! Give extra room around the stencil so you can secure it later when applying solderpaste.

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