Abstract:
Electromigration in microbump connections causes voids in the microbumps, which reduces the lifetime of an integrated circuit containing the microbump. Electromigration lifetime may be increased in microbumps by forming a copper shell around the solder. The copper shell of one microbump contacts the copper shell of a second microbump to enclose the solder of the microbump connection. The copper shell allows higher current densities through the microbump. Thus, smaller microbumps may be manufactured on a smaller pitch without suffering failure from electromigration. Additionally, the copper shell reduces shorting or bridging between microbump connections on a substrate.
Abstract:
A flip-chip electrical coupling between first and second electrical components (250, 260). The coupling includes a bump (210) and a pad (220). The bump (210) is electrically coupled to the first electrical component (250). The pad (220) is electrically coupled to the second electrical component (260). The pad (220) is electrically coupled to and dimensioned smaller than a corresponding coupling surface (214) of the bump (210). The pad (220) and bump (210) may be electrically coupled together using an ultrasonic stub bump bonding process, conductive epoxy, etc.
Abstract:
A high current semiconductor device (for example QFN for 30 to 70 A) with low resistance and low inductance is encapsulated by molding compound (401, height 402 about 0.9 mm) so that the second lead surfaces (110b) remain un-encapsulated. A copper heat slug (404) may be attached to chip surface (101b) using thermally conductive adhesive (403). Chip surface (101a), protected by an overcoat (103) has metallization traces (102). Copper-filled windows contact the traces and copper layers (105) parallel to traces. Copper bumps (108) are formed on each line in an orderly and repetitive arrangement so that the bumps of one line are positioned about midway between the bumps of the neighboring lines. A substrate has elongated leads (110) oriented at right angles to the lines; the leads connect the corresponding bumps of alternating lines.
Abstract:
Compression cold welding methods, joint structures, and hermetically sealed containment devices are provided. The method includes providing a first substrate having at least one first joint structure which comprises a first joining surface, which surface comprises a first metal; providing a second substrate having at least one second joint structure which comprises a second joining surface, which surface comprises a second metal; and compressing together the at least one first joint structure and the at least one second joint structure to locally deform and shear the joining surfaces at one or more interfaces in an amount effective to form a metal-to-metal bond between the first metal and second metal of the joining surfaces. Overlaps at the joining surfaces are effective to displace surface contaminants and facilitate intimate contact between the joining surfaces without heat input. Hermetically sealed devices can contain drug formulations, biosensors, or MEMS devices.
Abstract:
The invention relates to a method of manufacturing a semiconductor device (10), wherein a semiconductor element (1) provided with a number of connection regions (2) is fitted between a first, electroconductive plate (3) and a second plate (4), wherein two connection conductors (3A, 3B) are formed, from the first plate (3), for the two connection regions (2A, 2B) of the element (1), wherein a passivating encapsulation (5) is provided between the plates (3, 4) and around the element (1), and wherein the device (10) is formed by applying a mechanical separating technique in two mutually perpendicular directions (L, M). In a method according to the invention, the connection conductors (3A, 3B) are formed by providing a mask (6) on the first conducting plate (3) in such a manner that a part (3C) of the plate (3) situated between the connection regions (2A, 2B) remains exposed, which part is subsequently removed by etching. Such a method enables a very compact discrete or at least semi-discrete semiconductor device (10) to be readily obtained at low cost, while a high yield is achieved. In a preferred embodiment, also further parts (3D) of the conducting plate (3) situated at the location where the device (10) is to be sawn, cut or broken remain uncovered by the mask (6) and are removed during etching.
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:
By dividing a single chip area into individual sub areas (200a, 200b, 200c on the basis of one or more stress relaxation regions 280a, 280b,) a thermally- induced stress in each of the sub areas may be reduced during operation of complex integrated circuits, thereby enhancing the overall reliability of complex metallization systems comprising low-k dielectric materials or ULK material. Consequently, a high number of stacked metallization layers in combination with increased lateral dimensions of the semiconductor chip (200) may be used compared to conventional strategies.
Abstract:
A plurality of trenched capacitors are grouped in phases. A control circuit switches each phase between charging and discharging states devised to supply one or more loads with controlled power.
Abstract:
A novel method is presented to provide ASICs with drastically reduced NRE and with volume flexibility. The invention includes a method of fabricating an integrated circuit, including the steps of: providing a semiconductor substrate, forming a borderless logic array including a plurality of Area I/Os (36) and also including the step of forming redistribution layer (32) for redistribution at least some of the Area I/Os for the purpose of the device packaging. The fabrication may utilize Direct Write e-Beam for customization. The customization step may include fabricating various types of devices at different volume from the same wafer.