Method and components for flip-chip bonding
AssigneeHesse & Knipps GmbH
InventorHans Hesse
Life of this patent
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Abstract
In the forms of a flip-chip package in which the contact elements of the chip are ultrasonically welded to the contact elements of the substrate, either the chip or the substrate or both are provided, prior to juxtaposition, with a bonding material which can be ultrasonically activated. During the ultrasonic welding process in which the contact elements of the chip and substrate are bonded together, the bonding material provides an additional attachment between the chip and substrate and eliminates the need for underfilling.
Claims20
A component adapted to form part of a flip-chip assembly upon welding of a chip member having conductive elements to a substrate member having conductive elements bonded to the conductive elements of the chip, said component comprising one of said members formed with a bonding material on a surface juxtaposable with the other of said members and adapted to bond said members together over at least a part of said surface and mechanically supplementing a bond between said conductive elements to hold said members together without underfilling.
A flip-chip assembly comprising:
- a chip formed with a surface and contact elements projecting from said surface;
- a substrate having a surface juxtaposed with the surface of said chip and having contact elements engageable by the contact elements of said chip and ultrasonically weldable thereto;
- and
- a layer of an ultrasonically activatable bonding material on at least one of said surfaces prior to juxtaposition of said surfaces for bonding said surfaces together without underfill.
A method of connecting a chip having contact elements projecting from a surface with a substrate having contact elements on a surface to be bonded to the surface of the chip, said method comprising the steps of:
- (a) prior to juxtaposition of said surfaces, applying to at least one of said surfaces at least over at least part of an area thereof a bonding material;
- (b) juxtaposing said surfaces with the contact elements of said chip in contact with the contact elements of said substrate and with said bonding material interposed between said surfaces;
- (c) ultrasonically welding the contact elements of said chip to the contact elements of said substrate;
- and
- (d) additionally bonding said chip to said substrate with said bonding material between said surfaces.
Dependencies are inferred from the claim text.