Abstract:
In some embodiments, to increase the height-to-pitch ratio of a solder connection that connects different structures with one or more solder balls, only a portion of a solder ball's surface is melted when the connection is formed on one structure and/or when the connection is being attached to another structure. In some embodiments, non-solder balls are joined by an intermediate solder ball (140i). A solder connection may be surrounded by a solder locking layer (1210) and may be recessed in a hole (1230) in that layer. Other features are also provided.
Abstract:
In some embodiments, to increase the height-to-pitch ratio of a solder connection that connects different structures with one or more solder balls, only a portion (510) of a solder ball's (140) surface is melted when the connection is formed on one structure (110) and/or when the connection is being attached to another structure (HOB). The structure (110) may be an integrated circuit, an interposer, a rigid or flexible wiring substrate, a printed circuit board, some other packaging substrate, or an integrated circuit package. In some embodiments, solder balls (140.1, 140.2) are joined by an intermediate solder ball (140i), upon melting of the latter only. Any of the solder balls (140, 140i) may have a non-solder central core (140C) coated by solder shell (140S). Some of the molten or softened solder may be squeezed out, to form a "squeeze-out" region (520, 520A, 520B, 520.1, 520.2). In some embodiments, a solder connection (210) such as discussed above, on a structure (110A), may be surrounded by a dielectric layer (1210), and may be recessed in a hole (1230) in that layer (1210), to help in aligning a post (1240) of a structure (HOB) with the connection (210) during attachment of the structures (110A, HOB). The dielectric layer (1210) may be formed by moulding. The dielectric layer may comprise a number of layers (1210.1, 1210.2), "shaved" (partially removed) to expose the solder connection (210). Alternatively, the recessed solder connections (210) may be formed using a sublimating or vapourisable material (1250), placed on top of the solder (210) before formation of the dielectric layer (1210) or coating solder balls (140); in the latter case, the solder (140C) sinks within the dielectric material (1210) upon removal of the material (1250) and subsequent reflow. The solder connections (210.1, 210.2) may be used for bonding one or more structures (HOB, HOC) (e.g. an integrated circuit die or wafer, a packaging substrate or a package) to a structure (110A) (a wiring substrate) on which a die (HOB) is flip-chip connected. The solder connections (210.1, 210.2) may differ from each other, in particular in height.
Abstract:
Microelectronic assemblies and methods for making the same are disclosed herein. In one embodiment, a method of forming a microelectronic assembly comprises: assembling first and second components (102, 128) to have first major surfaces (104, 130) of the first and second components (102, 128) facing one another and spaced apart from one another by a predetermined spacing, the first component (102) having first and second oppositely-facing major surfaces (104, 106), a first thickness extending in a first direction between the first and second major surfaces (104, 106), and a plurality of first metal connection elements (112) at the first major surface (104), the second component (128) having a plurality of second metal connection elements (132) at the first major surface (130) of the second component (128); and then plating (electroplating or electroless plating) a plurality of metal connector regions (146) each connecting and extending continuously between a respective first connection element (112) and a corresponding second connection element (132) opposite the respective first connection element (112) in the first direction. The first and second metal connection elements (112, 132) may comprise metal vias (116, 134) in the components (102, 128) or metal pads (118) at the surface of the components (102, 128), the metal vias (116, 134) or the metal pads (118) being covered by plated metal regions (114). A first seed layer (126) may be formed overlying the major surface of the first component (102) before the plating process, wherein uncovered portions of the first seed layer (126) are removed after plating the metal connector regions (146). Similarly, a second seed layer (144) may be formed overlying the major surface of the second component (128). A plurality of barrier regions (152) may overlie the sidewalls of at least one of the metal connector regions (146), the first plated metal regions (114) or the second plated metal regions. At least some corresponding first and second metal connection elements (112, 132) may optionally not share a common axis. At least some first and second surfaces (113, 131) of the first metal connection elements (112) and the respective second metal connection elements (132) connected thereto may optionally not be parallel to a common plane.
Abstract:
In some embodiments, to increase the height-to-pitch ratio of a solder connection that connects different structures with one or more solder balls, only a portion (510) of a solder ball's (140) surface is melted when the connection is formed on one structure (110) and/or when the connection is being attached to another structure (HOB). The structure (110) may be an integrated circuit, an interposer, a rigid or flexible wiring substrate, a printed circuit board, some other packaging substrate, or an integrated circuit package. In some embodiments, solder balls (140.1, 140.2) are joined by an intermediate solder ball (140i), upon melting of the latter only. Any of the solder balls (140, 140i) may have a non-solder central core (140C) coated by solder shell (140S). Some of the molten or softened solder may be squeezed out, to form a "squeeze-out" region (520, 520A, 520B, 520.1, 520.2). In some embodiments, a solder connection (210) such as discussed above, on a structure (110A), may be surrounded by a dielectric layer (1210), and may be recessed in a hole (1230) in that layer (1210), to help in aligning a post (1240) of a structure (HOB) with the connection (210) during attachment of the structures (110A, HOB). The dielectric layer (1210) may be formed by moulding. The dielectric layer may comprise a number of layers (1210.1, 1210.2), "shaved" (partially removed) to expose the solder connection (210). Alternatively, the recessed solder connections (210) may be formed using a sublimating or vapourisable material (1250), placed on top of the solder (210) before formation of the dielectric layer (1210) or coating solder balls (140); in the latter case, the solder (140C) sinks within the dielectric material (1210) upon removal of the material (1250) and subsequent reflow. In some embodiments, the solder connections (210) may also be formed in openings (2220) in a dielectric layer (2210) (photoimageable polymer or inorganic) by solder paste printing and/or solder ball jet placement followed by reflow to let the solder sink to the bottom of the openings (2220), with possible repetition of the process and possible use of different solders in the different steps. The solder connections (210, 210.1, 210.2) may be used for bonding one or more structures (HOB, HOC) (e.g. an integrated circuit die or wafer, a packaging substrate or a package) to a structure (110A) (a wiring substrate) on which a die (HOB) is flip-chip connected. The solder connections (210, 210.1, 210.2) may differ from each other, in particular in height, which can be used for attaching a structure (HOB) with posts (1240) of different heights or for attaching two structures (HOB, HOC) in the case of a stepped form of the dielectric layer, one of the structures (HOC) being possibly placed higher than the other structure (HOB). In some embodiments, the structure (HOA) may be removed after bonding to the structures (HOB, HOC) and a redistribution layer (3210) may be formed to provide connecting lines (3220) connecting the solder connections (210) to contact pads (120R) and possibly interconnecting between the solder connections (210) and/or between the contact pads (120R).