What is the recommended dispense pattern for underfilling flip chips?
The recommended dispense pattern depends on factors such as die size and bump layout. A 60-80% line is generally recommended for higher UPH and easier programming. An L-pattern may be used, however, needle crashing into the die corner and a void at the opposite corner are common concerns related to the use of L-pattern. A shorter line centered along the die side is recommended in order to force the flow front down the center of the die.
