摘要:
Start with a semiconductor substrate with contacts exposed through an insulating layer. Form a base over the contacts, with the base composed of at least one metal layer. Then form a conductive metal layer over the base. Form a mask over the top surface of the conductive metal layer with C4 solder bump openings therethrough with the shape of C4 solder bump images down to the surface of the conductive metal layer above the contacts. Etch away the exposed portions of the conductive metal layer below the C4 solder bump openings to form through holes in the conductive metal layer exposing C4 solder bump plating sites on the top surface of the base below the C4 solder bump openings with the conductive metal layer remaining intact on the periphery of the through holes at the C4 solder bump plating sites. As an option, form a barrier layer over the plating sites next. Form C4 solder bumps on the plating sites on the base/barrier layer within the C4 solder bump openings, with the C4 solder bumps being in contact with the conductive metal layer on the periphery of the through holes. Remove the mask. Etch away the remainder of the conductive metal layer, and etch away the base aside from the C4 solder bumps forming BLM pads. Then reflow the C4 solder bumps to form C4 solder balls.
摘要:
A method of forming wire bonds in (I/C) chips comprising: providing an I/C chip having a conductive pad for a wire bond with at least one layer of dielectric material overlying the pad; forming an opening through the dielectric material exposing a portion of said pad. Forming at least a first conductive layer on the exposed surface of the pad and on the surface of the opening. Forming a seed layer on the first conductive layer; applying a photoresist over the seed layer; exposing and developing the photoresist revealing the surface of the seed layer surrounding the opening; removing the exposed seed layer; removing the photoresist material in the opening revealing the seed layer. Plating at least one second layer of conductive material on the seed layer in the opening, and removing the first conductive layer on the dielectric layer around the opening. The invention also includes the resulting structure.
摘要:
A method of forming wire bonds in (I/C) chips comprising: providing an I/C chip having a conductive pad for a wire bond with at least one layer of dielectric material overlying the pad; forming an opening through the dielectric material exposing a portion of said pad. Forming at least a first conductive layer on the exposed surface of the pad and on the surface of the opening. Forming a seed layer on the first conductive layer; applying a photoresist over the seed layer; exposing and developing the photoresist revealing the surface of the seed layer surrounding the opening; removing the exposed seed layer; removing the photoresist material in the opening revealing the seed layer. Plating at least one second layer of conductive material on the seed layer in the opening, and removing the first conductive layer on the dielectric layer around the opening. The invention also includes the resulting structure.
摘要:
A low impedance power distribution structure and method for substrate packaging of semiconductor chips containing very large scale integrated circuit (VLSI) circuits, such as microprocessors and associated memory, is presented. The power distribution structure incorporates under bump metallurgy (UBM) solder bump forming technology to produce not only solder bump connections that are vertically oriented, but also low impedance distribution wires that are horizontally oriented, and which provide electrical interconnection between various selected electrical contact points, such as solder bumps. These low impedance distribution wires introduce the benefits of low characteristic impedance to the substrate's power distribution structure.
摘要:
A multi-layer pillar is provided. The multi-layer pillar is used as an interconnect between a chip and substrate. The pillar has at least one low strength, high ductility deformation region configured to absorb force imposed during chip assembly and thermal excursions.
摘要:
Disclosed are embodiments of a flip-chip assembly and method using lead-free solder. This assembly incorporates mushroom-plated metal layers that fill and overflow solder resist openings on an organic laminate substrate. The lower portion of metal layer provides structural support to its corresponding solder resist opening. The upper portion (i.e., cap) of each metal layer provides a landing spot for a solder joint between an integrated circuit device and the substrate and, thereby, allows for enhanced solder volume control. The additional structural support, in combination with the enhanced solder volume control, minimizes strain on the resulting solder joints. Additionally, the cap further allows the minimum diameter of the solder joint on the substrate-side of the assembly to be larger than the diameter of the solder resist opening. Thus, the invention decouples C4 reliability concerns from laminate design concerns and, thereby, allows for greater design flexibility.
摘要:
An etchant which includes an aqueous solution of between about 30% and about 38% concentrated hydrogen peroxide, said percentages being by volume, based on the total volume of the solution; between about 3.5 ml and about 20 ml per liter of phosphoric acid; and an amount of potassium hydroxide to adjust the pH of the solution to between about 7.8 and about 9.1. The etchant is useful in removing a layer of an alloy of titanium and tungsten or a layer of tungsten from a precision surface.
摘要:
Form a solder connector on a semiconductor device starting with a first step of forming at least one dielectric layer over a doped semiconductor substrate. Then form a hole through the dielectric layer down to the semiconductor substrate. Form a metal conductor in the hole. Form intermediate layers over the metal conductor and the dielectric layer. Then form a tapered opening down to the surface of the metal conductor. Form BLM layers including a titanium-tungsten (TiW) layer over the metal conductor and the dielectric layer with the remainder of the BLM layers being formed over the TiW layer. Form a mask over the top surface of the BLM layers with a patterning through hole located above the metal conductor exposing a portion of the surface of the BLM layers. Plate a C4 solder bump on the BLM layers in the patterning hole. Remove the mask. Wet etch away the BLM layers aside from the solder bump leaving a residual TiW layer over the dielectric layer. Perform a dry etching process to remove the residual TiW layer aside from the solder bump. Then, end the dry etching when the end point has been reached. Finally, heat the solder bump in a reflow process to form a C4 solder ball.
摘要:
Briefly, a novel material process is disclosed wherein one or more nucleation modifiers are added, in trace amounts, to a lead-free tin-rich solder alloy to produce a solder composition with reduce or suppressed undercooling temperature characteristics. The modifier being a substance which facilitates the reduction of extreme anisotropic properties associated with body-centered-tetragonal tin based lead-free solder. The addition of the nucleation modifiers to the solder alloy does not materially effect the solder composition's melting point. As such, balls of solder with the nucleated composition freeze while other solder balls within the array remain in the melt. This effectively enables one substrate to be pinned to another substrate by one or more predetermined solder balls to secure the package while the remaining solder joints are in the liquid state. Further, the addition of a trace amount of nucleation sites within the composition facilitates control over the number, size, and orientations of primary intermetallic compounds in tin rich crystallite grains. Moreover, trace amounts of one or more solid and/or insoluble nucleating modifiers within a given volume of solder reduces the size of average crystallites within the composition.
摘要:
In one embodiment of the present invention, inert nano-sized particles having dimensions from 1 nm to 1,000 nm are added into a solder ball. The inert nano-sized particles may comprise metal oxides, metal nitrides, metal carbides, metal borides, etc. The inert nano-sized particles may be a single compound, or may be a metallic material having a coating of a different material. In another embodiment of the present invention, a small quantity of at least one elemental metal that forms stable high melting intermetallic compound with tin is added to a solder ball. The added at least one elemental metal forms precipitates of intermetallic compounds with tin, which are dispersed as fine particles in the solder.