Solder-bumped semiconductor substrates (e.g., semiconductor wafers) and methods for forming solder bumped semiconductor substrates are provided, in which solder bumps are formed on a semiconductor substrate using preformed solder balls having different compositions and/or sizes. Two or more solder balls masks are successively utilized to place different types of preformed solder balls (differing in composition and/or size) into corresponding cavities of a solder ball fixture, and thereby form an array of different types of preformed solder balls arranged in the solder ball fixture. The array of preformed solder balls in the solder ball fixture are then transferred to corresponding contact pads of a semiconductor substrate (e.g., semiconductor wafer) using a single solder reflow process. This process allows different types of preformed solder bumps to be bonded to a semiconductor substrate at the same time using a single solder reflow process.

A method includes performing a first strike process to strike a metal bump of a first package component against a metal pad of a second package component. A first one of the metal bump and the metal pad includes copper. A second one of the metal bump and the metal pad includes aluminum. The method further includes performing a second strike process to strike the metal bump against the metal pad. An annealing is performed to bond the metal bump on the metal pad.

A method of forming a structure for an interfacial alloy layer which is able to improve the electromigration (EM) resistance of a solder joint. More specifically, in this structure, a controlled interfacial alloy layer is provided on both sides of a solder joint. In order to form this structure, aging (maintenance of high-temperature conditions) is performed until an interfacial alloy layer of Cu3Sn has a thickness of at least 1.5 m.

A bump structure includes a pad. A passivation layer covers a perimeter of the pad. The passivation layer includes an opening exposing an area of the pad. A first portion is disposed on the pad. The first portion includes a top surface and a sidewall. A second portion covers the top surface and entire sidewall of the first portion.

A method and device are provided wherein a first semiconductor device and a via are encapsulated with an encapsulant. A redistribution layer connects the first semiconductor device to a second semiconductor device. In a particular embodiment the first semiconductor device is an integrated voltage regulator and the second semiconductor device is a logic device such as a central processing unit.

Solder-bumped semiconductor substrates (e.g., semiconductor wafers) and methods for forming solder bumped semiconductor substrates are provided, in which solder bumps are formed on a semiconductor substrate using preformed solder balls having different compositions and/or sizes. Two or more solder balls masks are successively utilized to place different types of preformed solder balls (differing in composition and/or size) into corresponding cavities of a solder ball fixture, and thereby form an array of different types of preformed solder balls arranged in the solder ball fixture. The array of preformed solder balls in the solder ball fixture are then transferred to corresponding contact pads of a semiconductor substrate (e.g., semiconductor wafer) using a single solder reflow process. This process allows different types of preformed solder bumps to be bonded to a semiconductor substrate at the same time using a single solder reflow process.

A photodetector-array and fabrication method thereof are disclosed. The photodetector-array includes a first and second semiconductor structures having respective active regions defining respective pluralities of active photodetectors and active readout integrated circuit pixels (RICPs) electronically connectable to one another respectively. The first and second semiconductor structures are made with different semiconductor materials/compositions having different first and second coefficients of thermal expansion (CTEs) respectively. The pitch distances of the active photodetectors and the pitch distances of the respective active RICPs are configured in accordance with the difference between the first and second CTEs, such that at high temperatures, at which electrical coupling between the first and second semiconductor structures is performed, the electric contacts of the active photodetectors and of their respective RICPs overlap. Accordingly, after the first and second semiconductor structures are bonded together, at least 99.5% of the active photodetector are electrically connected with their respective RICPs.

Methods for die attachment of multichip and single components including flip chips may involve printing a sintering paste on a substrate or on the back side of a die. Printing may involve stencil printing, screen printing, or a dispensing process. Paste may be printed on the back side of an entire wafer prior to dicing, or on the back side of an individual die. Sintering films may also be fabricated and transferred to a wafer, die or substrate. A post-sintering step may increase throughput.

A thermocompression bonding system for bonding semiconductor elements is provided. The thermocompression bonding system includes (1) a bond head assembly including a heater for heating an semiconductor element to be bonded, the bond head assembly including a fluid path configured to receive a cooling fluid; (2) a pressurized cooling fluid source; (3) a booster pump for receiving a pressurized cooling fluid from the pressurized cooling fluid source, and for increasing a pressure of the received pressurized cooling fluid; (4) a pressurized fluid reservoir for receiving pressurized cooling fluid from the booster pump; and (5) a control valve for controlling a supply of pressurized cooling fluid from the pressurized fluid reservoir to the fluid path.

An electrical apparatus includes a first electrical component; a second electrical component; and an InSnAg alloy connecting the first electrical component and the second electrical component, the InSnAg alloy containing AgIn.sub.2 and Ag.sub.2In, a Ag.sub.2In content being lower than a AgIn.sub.2 content.