Underfill material dispensing for stacked semiconductor chips
A template having tapered openings can be employed to enable injection of underfill material through gaps having a width less than a lateral dimension of an injector needle for the underfill material. Each tapered opening has a first lateral dimension on an upper side and a second lateral dimension on a lower side. Compliant material portions can be employed to accommodate variations in distance between the template and stacked semiconductor chips and/or an injector head. Optionally, another head can be employed to apply compressed gas to push out the underfill material after the underfill material is applied to the gaps. Multiple injector heads can be employed to simultaneously inject the underfill material at different sites. An adhesive layer can be substituted for the at least one lower compliant material portion.
1. A structure comprising at least:
a template, said template including a plurality of template openings extending between a first surface and a second surface of said template, wherein each of said plurality of template openings has a first lateral dimension at said first surface and has a second lateral dimension that is greater than said first lateral dimension at said second surface, wherein said plurality of template openings is a two-dimensional periodic array of openings having a periodicity in two horizontal directions; and
an injector head containing an underfill material and overlying one of said plurality of template openings and including an injector tip and an injector manifold configured to hold an underfill material prior to injection.
2. The structure of claim 1 , wherein each of said plurality of template openings has a non-zero taper angle relative to a surface normal of a distal surface of said template that is selected said first surface and said second surface.
3. The structure of claim 1 , further comprising a compliant material layer including at least one lower compliant material portion and disposed directly on said template.
4. The structure of claim 3 , wherein said compliant material layer includes a plurality of compliant material openings that underlies said plurality of template openings.
5. The structure of claim 1 , further comprising an adhesive layer disposed directly on said template layer.
6. The structure of claim 5 , wherein said adhesive layer comprises a plurality of adhesive layer openings that underlie said plurality of template openings.
7. The structure of claim 6 , wherein each of said adhesive layer openings has a lateral dimension that is less than said first lateral dimension.