Method for dispensing underfill and devices formed
AssigneeIndustrial Technology Research Institute
InventorsShih Hsiung Lin, Hsing Seng Wang
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Abstract
A method for dispensing underfill in a flip chip package formed of an IC chip and a substrate and devices formed by such methods are disclosed. The method for dispensing may be carried out by either a screen printing (or stencil printing) or a dispensing head process wherein droplets of an underfill material may be dispensed on the surface of an IC die or a substrate. Numerous benefits may be achieved by the present invention for dispensing an underfill material which includes shorter cycle time, superior quality product and more flexible processing parameters. The underfill material may be cured in the same reflow furnace during the reflow process for the solder balls such that a separate curing process can be eliminated.
Claims12
A method for dispensing underfill in a flip chip package formed of an IC chip and a substrate comprising the steps of:
- providing a flip chip package of an IC chip bonded to a substrate by a plurality of spaced-apart solder balls, a gap formed between said IC chip, said substrate and said plurality of solder balls,
- positioning a stencil on top of and in intimate contact with a top surface of said IC chip, said stencil being provided with at least two slot openings corresponding to at least two adjacent edges of said IC chip such that said at least two slot openings are in fluid communication with said gap, and
- flowing an underfill material across a top surface of said stencil in a direction toward said IC chip such that said underfill material flows through said at least two slot openings and filling said gap between said IC chip, said substrate and said plurality of spaced-apart solder balls.
Dependencies are inferred from the claim text.