Determining Pick Height and Place Height

Ensuring proper pick height and place height is crucial for the accurate placement of each component onto your printed circuit board. Of course, it is called a pick and place machine after all, so getting the measurements correct is essential!

Finding the Pick Height: A Checklist for Success

When determining the Pick Height, it is essential that you follow these guidelines to ensure your machine functions properly when picking up components.

1. Positioning: When positioning the placement head over a component, be sure it is centered over a component in your tape feeder.
2. Avoid: Do not move the placement head too far down onto the surface of a component. If lowered too far, it can create issues during picking such as:
   1. Components sliding around in the tape pocket when being picked
   2. Tombstone picks.
3. Gentle Contact: Lower the placement head just enough to make gentle contact between the nozzle and the component to ensure the nozzle can pick up the component.

Establishing the Pick Height: Steps for Success

The Pick Height tells the placement head the distance between the nozzles and the top of a component in a tape feeder to avoid errors when picking up components. Follow these steps to determine Pick Height.

1. Access: Enter the Manual Test page from the home screen on the YY1 user interface. 

2. Positioning the Head: Use the placement head arrows to drive Head 1 over to a component in a tape feeder. Center the head above one exposed component that is next in line to be picked.
3. Lowering the Head: Use the green “Up” and “Down” buttons inside the Head 1 box to lower the head until it just slightly touches the top of the component. As you lower the head, the value listed to the right of the green buttons inside the Head 1 box will increase. The final number should be between 19.0mm and 21.0mm.

4. Calculating Pick Height: Note this number and calculate the Pick Height by subtracting it from the Nozzle Height Datum (default value 20.00mm), which can be found on the Parameters Page.  It is possible the correct value will be negative. 
5. Ensuring Gentle Contact: It is necessary to ensure gentle contact between the nozzle and the component. To do this, it is best if you subtract an extra 0.2mm-0.3mm to allow room for a smooth connection.

Establishing the Place Height: A Checklist for Success

When determining the Place Height, it is essential that you follow these guidelines to ensure your machine functions properly when placing components.

1. Positioning: When positioning the placement head over the board, be sure it is centered over an open space within the working surface area of the PCB.
2. Avoid: Do not lower the nozzle too far down onto the board. If lowered too far, it can create issues during placement such as:
   1. The board moving or bending.
   2. Z-axis error requiring reboot
3. Gentle Contact: Lower the placement head just enough to make gentle contact between the nozzle and the board to ensure gentle spring compression and proper adhesion.

Establishing the Place Height: Steps for Success

The Place Height measures the distance from the nozzles to the surface area of the PCB to determine the height of the PCB when mounted. Follow these steps to determine Place Height.

1. Access: Enter the Manual Test page from the home screen on the YY1 user interface. (see picture above)
2. Position the Head: Use the placement head arrows and drive the head over to the printed circuit board. Locate an open area on the board free of any parts or other obstacles. 
3. Lowering the Head: Lower the head using the green “Up” and “Down” buttons inside the Head 1 box until it just slightly touches the surface of the board. The value listed to the right of the green buttons inside the head 1 box will increase as you lower the head. This number should also be between 19.0mm-21.0mm.

3. Calculating Base Place Height: Note this number and calculate the base place height by subtracting the number noted from the Nozzle Height Datum (20.00mm).  It is possible the correct value will be negative.
4. Calculating Final Place Height: Now take the calculated number noted as the base place height and add it to the thickness of the component.
5. Ensuring Gentle Spring Compression: As noted under A Checklist for Success, it is necessary to ensure gentle spring compression when placing the component onto the board to guarantee proper adhesion between the component and the solder paste. To do this, it is best if you subtract an extra 0.2mm-0.3mm to allow room for a smooth connection.

By following these steps, you’ll have your pick and place machine ready for accurate component placement in no time.