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:
A vacuum-application and coating apparatus (27) for applying a protective coating (17) to at least one ball-grid-array assembly is provided. The apparatus comprises an upper plate (29) having at least one injection port (37) forming the upper chamber wall, and a lower plate (31) having at least one vacuum port (35) forming the lower chamber wall of the vacuum-application and coating apparatus when assembled. A compliant layer of material is provided on the chamber-side surface of the upper plate and a sealing mechanism (33) for enabling a vacuum seal is also provided. At least one ball-grid-array assembly is placed on the chamber surface of the lower plate during assembly of the vacuum-application and coating apparatus, which forms a vacuum chamber. The ball-grid-array assemblies held in the chamber are protected from receiving any coating on the upper portions of connected solder balls during processing by virtue of intimate contact between the solder balls and the compliant layer of material. In other aspects methods are provided for adding a protective coating (17) to ball-grid-array assemblies (14) and subsequently providing opening for access to the die pads (11). In another aspect a process is provided for completely encapsulating balls (15), then exposing a portion and applying a new grid array.
Abstract:
A structure (10) may include bond elements (24) having bases joined to conductive elements (18) at a first portion of a first surface and end surfaces remote from the substrate (12). A dielectric encapsulation element (40) may overlie and extend from the first portion and fill spaces between the bond elements (24) to separate the bond elements (24) from one another. The encapsulation element (40) has a third surface facing away from the first surface. Unencapsulated portions of the bond elements (24) are defined by at least portions of the end surfaces uncovered by the encapsulation element at the third surface. The encapsulation element (40) at least partially defines a second portion (210) of the first surface that is other than the first portion and has an area sized to accommodate an entire area of a microelectronic element (602). Some conductive elements (18) are at the second portion and configured for connection with such microelectronic element (602).
Abstract:
A method is provided for forming a microelectronic assembly. A semiconductor substrate (20) having a first thickness is mounted to a support substrate (28) with a low temperature adhesive. The semiconductor substrate is thinned from the first thickness to a second thickness. At least one contact formation (50) is formed on the semiconductor substrate, and high energy electromagnetic radiation (56) is directed onto the at least one contact formation to reflow the at least one contact formation.
Abstract:
A plurality of resin layers (40, 100), wiring (20) connected electrically to electrodes (14) of semiconductor elements (12) and external terminals (30) connected electrically to the wiring are formed on a collection (10) of the semiconductor elements (12). The collection (10) is cut. At least one of the resin layers (40, 100) is deviated from the regions (70) where the collection (10) is cut.
Abstract:
Improved Molded Laser Package (MLP) Packages which include a relief path for pressure and reduces the risk of shorting adjacent solder balls are provided. The MLP packages may include a gutter integrally connected to one or more through mold vias allowing a path to relieve pressure created when moisture gets entrapped in through mold vias, during the manufacturing process, while also reducing the risk of solder shorts between adjacent solder balls located in the through mold vias. Additionally, MLP packages which include gutters integrally connected to one or more through mold vias may enable tighter bump pitch and thinner packages. As a result, process margins and risks associated with surface mount technology (SMT) may be improved and provide more flexibility on inventory staging.
Abstract:
A barrier layer deposited on the passivation layer of a semiconductor die decreases adhesion of glue used during stacking of semiconductor dies by altering chemical or structural properties of the passivation layer. During detachment of a carrier wafer from a wafer, the barrier layer reduces glue residue on the wafer by modifying the surface of the passivation layer. The barrier layer may be insulating films such as silicon dioxide, silicon nitride, silicon carbide, polytetrafluoroethylene, organic layers, or epoxy and may be less than two micrometers in thickness. Additionally, the barrier layer may be used to reduce topography of the semiconductor die to decrease adhesion of glues.