Mock Build

Mar 25 2016

After four excruciating days I have finally built the mock board. The second run went flawlessly. The third run at 100% speed finished flawlessly with one rejected pick.

The next step is to load the tray (cut tape) components and build. The tray components are the TC33 and U-A3967SLB. {THREAD_LINK:1395}

Take a close-up photo of the tray components in their original tape before removing the cover tape to record how the parts are oriented in relation to the sprocket holes. It is extremely likely I will be replacing the components and I will need to know how they are placed. This information is also in the packaging information of the datasheet, but a photo is easier.

The TC-33X is oriented in the tape with the notch toward the sprocket, the two pins away. The second diagram shows the footprint.

The A3967 is oriented with the notch toward the sprocket.

Use painter's masking tape to secure the feeder tape in the tray and for labeling. Masking tape is easier to remove than celophane tape. Do not write directly on the tray!

Test

I need to test the pick and place operations. If I have restarted Place since building the last board I will need to go through Learn Reference Points again to set the fiducials, reference points, and horizontal line.

1. Open "Learn Place"
2. Click "Skip All"
3. Uncheck (to unskip) one of the A3967 components.
4. Click OK to close Learn Place.
5. Open Auto Production
6. Click Start
7. Verify that only the single A3967 component will be placed.
8. Run production
9. Compare the actual placement against the layout, paying close attention to the orientation of the part on the board.
10. Remove the component from the board and replace it in its original tray location, paying close attention to the orientation of the part in the tray.
11. Open "Learn Pick"
12. Select the tray tab
13. Reset "QFN No" for the A3967 component back to 1.
14. Click OK

SUCCESS! It worked. I am now ready to order the boards and stencil.

Replace the larger, more expensive components in their cut tape receptacles and secure them in place with tape. It is not worth the trouble for smaller components, certainly not for resistors, caps, and leds. Tiny components live in a different universe where Newtonian physics don't always apply. For 0402 parts, static electricity is much stronger than gravity and they will fly through space seemingly at random.