Flip-chip assembly of semiconductor devices using adhesives
AssigneeInteruniversitair Microelektronica Centrum vzw
InventorsJan Vanfleteren, Sergei Stoukach, Bjorn Vandecasteele
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Abstract
The present invention is related to a flip-chip-on-board (FCOB) assembly technology applicable for mounting large chips with high I/O count or small pitch, mounted on low-cost or low-grade substrates. The assembly technology uses both an isotropically conductive adhesive (ICA) and a non-conductive material (NCA) in the same assembly cycle. The thermocompression step establishes at the same time the electrical and mechanical interconnections and the curing of the adhesives.
Claims33
Process for manufacturing an apparatus comprising at least one substrate and at least one component, said substrate having a surface with a plurality of bonding pads which are metal, said component having a plurality of bonding pads, the bonding pads on the substrate corresponding to the bonding pads on the component, said component being attached to and in electrical contact with said substrate, characterized in that said process comprises the following steps:
- dispensing an adhesive onto said bonding pads of said substrate or onto said bonding pads of said component;
- drying said adhesive;
- applying an underfill material on an area situated between said bonding pads of said substrate;
- aligning the bonding pads of said component with at least some of the bonding pads of the substrate;
- exerting a mechanical pressure on said component;
- and
- curing said adhesive and said underfill material, said step of curing being performed while maintaining said mechanical pressure, thereby creating electrical contacts between said component and said substrate,
- wherein during the step of exerting a mechanical pressure on said component, said underfill material substantially fills the non-bonding area of the substrate.
Process for manufacturing an apparatus comprising at least one substrate and at least one component, said substrate having a surface with a plurality of bonding pads which are metal, said component having a plurality of bonding pads, the bonding pads on the substrate corresponding to the bonding pads on the component, said component being attached to and in electrical contact with said substrate, characterized in that said process comprises the following steps:
- dispensing an adhesive onto said bonding pads of said substrate or onto said bonding pads of said component;
- drying said adhesives;
- applying an underfill material on an area situated between said bonding pads of said substrate;
- aligning the bonding pads of said component with at least some of the bonding pads of the substrate;
- exerting a mechanical pressure on said component;
- and
- curing said adhesive and said underfill material, said step of curing being performed while maintaining said mechanical pressure, thereby creating electrical contacts between said component and said substrate,
- wherein the material of said substrate is selected from the group consisting of FR4, FR5, glass-epoxy materials, ceramic materials, polyimide, polyester, alumina based materials and plastic materials,
- wherein said component is chosen from the group consisting of a packaged semiconductor chip, and non-packaged semiconductor chip, a naked semiconductor die and a component made of a non-semiconductor material,
- wherein said adhesive comprises a non-conductive epoxy and at least 80 weight percent of silver flakes,
- wherein said underfill material is a non-conducting adhesive (NCA),
- wherein said NCA is a non-conducting epoxy,
- wherein said drying step is performed in an oven at a temperature below the curing temperatures of both the adhesive and the underfill material.
Process for manufacturing an apparatus comprising at least one substrate and at least one component, said substrate having a surface with a plurality of bonding pads which are metal, said component having a plurality of bonding pads, the bonding pads on the substrate corresponding to the bonding pads on the component, said component being attached to and in electrical contact with said substrate, characterized in that said process comprises the following steps:
- dispensing an adhesive onto said bonding pads of said substrate or onto said bonding pads of said component;
- drying said adhesive;
- applying an underfill material on an area situated between said bonding pads of said substrate;
- aligning the bonding pads of said component with at least some of the bonding pads of the substrate;
- exerting a mechanical pressure on said component;
- and
- curing said adhesive and said underfill material, said step of curing being performed while maintaining said mechanical pressure, thereby creating electrical contacts between said component and said substrate,
- wherein said step of drying being performed at a temperature below the curing temperatures of both the adhesive and the underfill material.
Dependencies are inferred from the claim text.