(2002), "New convertible head flip chip bonder", Microelectronics International, Vol. 19 No. 1. https://doi.org/10.1108/mi.2002.21819aad.003
Emerald Group Publishing Limited
Copyright © 2002, MCB UP Limited
New convertible head flip chip bonder
Keywords: Flip chip, Bonding
A new development of the PESL. DB5-TSV vertical head ultrasonic flip chip bonder flow allows for rapid conversion to horizontal ultrasonics and with a standard head it enables use as a highly accurate pick and place machine.
The vertical ultrasonic head enables improved planar attachment of very fragile chips such as galium arsonide and for some of the very small microwave chips presently in development. Conventional gold bump chips can then be bonded using either horizontal or vertical ultrasonics, involving only a quick and simple change of the active head unit.
Without either ultrasonic head the DB5 is a very accurate flip chip pick and place machine for normal reflow, or for pick, epoxy, place and reflow.
In vertical ultrasonic format the PESL DB5 - TSV unit offers accuracy of 2-3µM and very low force on the chip. The unit was developed especially for small chips with gold contacts- generally these have required high force to adequately bond with vibration transmitted across the chip. However, using a vertical application of the ultrasonic wave, bonding reliability is greatly improved. This is especially true where planarity problems on large chips can be eliminated; thus generating greatly improved yields. Planarity refers to the tendency for large chips to tilt, thus leaving some balls off the bond plane and not connecting.
Further information regarding PFSL products may be found at: www.pesl.win-uk.net