Pick & Place - The Concept

Careful die handling is paramount to maintain overall quality and good die yields from the wafer once it has been sawn.  Due to the delicate nature of the product (particularly on the active side of the die), using a Pick and Place machine allows us to apply the absolute minimum contact and relative force required to remove die from the foil ring frame after saw. Although there are circumstances where a degree of manual removal is necessary it is always preferable to opt for an automated process by using a Pick & Place machine as the possibility mechanical damage to the die is greatly reduced.  Pick & Place automation is also necessary to deal with high volumes and enables us to offer fast output turn-arounds which are simply not possible otherwise.  A good example to use would be a small transistor, even our most dextrous and experienced clean room operative could not hope to manually remove 1,750 die in an hour!  Lastly, the use of an automatic Pick and place machine also enables us to guarantee 100% die orientation, this ensures complete compatibility with end customer equipment where once again high-speed production is required.

Pick & Place - The Process

The sawn wafer remains on the ring frame and is fixed to a plate in the centre of the Pick & Place machine.  The foil supporting the sawn wafer is now stretched to increase the space between each die. The operator manually adjusts the X & Y co-ordinates to centre on a die by viewing it on a magnified screen.  The actual die are removed from the foil through the use of single or multiple ejector pins which push up from under the foil and release the die by applying pressure to the backside.  To collect the raised die, a vacuum powered mechanical arm sweeps across, picks up the die and releases it into the appropriate carrier.  Although the Pick & Place machine requires expert calibration to set-up, once this is done an operator can systematically remove the die one by one from the foil and deposit them into their chosen output carrier very quickly.

Pick & Place - Capabilities

• Royce Instruments Inc. Model DE35 Die Pick & Place Systems ( two Systems currently in use) both with colour zoom CCTV

• Delicate die handling

• Up to 6" (150mm) wafer diameter capability

• Picks die from 0.008" to over 0.6" sq.

• Safe handling of 'bumped' die for 'flip-chip' applications

• Die can be sorted into waffle or vacuum-release (Gelpack) trays

• Automatic die orientation

• Fast turn-around for volume orders