Advanced Semiconductor Engineering, Inc.

Yu-Chen Chou

Ho-Ming Tong

Jen-Kuang Fang

Chun-Chi Lee

Min-Lung Huang

Chao-Fu Weng

Ching-Huei Su

Jau-Shoung Chen

Yung-Chi Lee

Su Tao

Tsung-Hua Wu

Chun-Hung Lin

Shyh-Ing Wu

Shih-Kuang Chen

Ching-Fu Horng

A wafer-level package structure, applicable to a flip-chip arrangement on a carrier, which comprises a plurality of contact points, is described. This wafer-level package structure is mainly formed with a chip and a conductive layer. The conductive layer is arranged on the bonding pads of the chip as contact points. The conductive layer can further be arranged at a region outside the bonding pads on the chip as a heat sink to enhance the heat dissipation ability of the package.

Wafer-level package structure

A bump fabrication process for forming a bump over a wafer having a plurality of bonding pads thereon is provided. A patterned solder mask layer having a plurality of openings that exposes the respective bonding pads is formed over a wafer. The area of the opening in a the cross-sectional area through a the bottom-section as well as through a the top-section of the opening is smaller than the area of the opening in a the cross-sectional area through a the mid-section of the opening. Solder material is deposited into the opening and then a reflow process is conducted fusing the solder material together to form a spherical bump inside the opening. Finally, the solder mask layer is removed. In addition, a pre-formed bump may form on the bonding pad of the wafer prior to forming the patterned solder mask layer over the wafer having at least with an opening that exposes the pre-formed bump. Solder material is deposited into the openings and then a reflow process is conducted fusing the solder material and the pre-formed bump together to form a spherical bump. The pre-formed bump and the solder material may be fabricated using different constituents.

Bump fabrication process

A semiconductor device with a capability can prevent a burnt fuse pad from re-electrical connection, wherein the semiconductor device includes a bump pad and a fuse pad over a wafer. The fuse pad includes the burnt fuse pad having a gap for electrical isolation. The semiconductor device comprises a dielectric layer, disposed substantially above the burnt fuse pad and filling the gap, and a bump structure, disposed on the bump pad. The foregoing semiconductor device can further comprise a passivation layer, which exposes the bump pad and a portion of the burnt fuse pad. Wherein, the dielectric layer is over the passivation layer, covers the exposed portion of the burnt fuse pad and fills the gap.

Structure for preventing burnt fuse pad from further electrical connection

A method of modifying the tin to lead ratio of a tin-lead bump forms a patterned solder mask over a substrate that comprises a first tin-lead bump formed thereon, the patterned solder mask having an opening that exposes the tin-lead bump. A solder material including tin and lead is filled in the opening of the solder mask over the first tin-lead bump. The solder material has a tin to lead ratio that differs from that of the first tin-lead bump. The solder material is reflowed to fuse with the first tin-lead bump, which forms a second tin-lead bump. The tin to lead ratio of the second tin-lead bump is thereby different from that of the first tin-lead bump.

Method of modifying tin to lead ratio in tin-lead bump

A solder ball fabricating process for forming solder balls over a wafer having an active layer is provided. A patterned solder mask layer is formed over the active surface of the wafer. The patterned solder mask layer has an opening that exposes a bonding pad on the wafer. Solder material is deposited into the opening over the bonding pad. A reflow process is conducted to form a pre-solder body. The aforementioned steps are repeated so that various solder materials are fused together to form a solder ball over the bonding pad.

Solder ball fabricating process

A wafer bump fabrication process is provided in the present invention. A wafer with multiple bonding pads and a passivation layer, which exposes the bonding pads, is provided. The surface of each bonding pad has an under bump metallurgy layer. A patterned photoresist layer with a plurality of opening is formed which openings expose the under bump metallurgy layer. Afterwards a curing process is performed to cure the patterned photoresist layer. Following a solder paste fill-in process is performed to fill a solder paste into the openings. A reflow process is performed to form bumps from the solder paste in the openings. The patterned photoresist layer is removed.

Process for fabricating wafer bumps

A method for preventing burnt fuse pads from further electrical connection suitable before the formation of bumps on the wafer. A dielectric layer is formed over the active surface of the wafer covering the bump pads and the fuse pads of the wafer, wherein a central region of the fuse pads is burnt to form a gap which allows the material of the dielectric layer to fill up the gap. Afterwards, either a part of the dielectric layer is removed and the part of the dielectric layer covering the fuse pads remainsor a part of the dielectric layer covering the bump pads is removed. Then, an under ball metallurgy layer is formed on the bump pads of the wafer so that the material of the under ball metallurgy layer does not cover the two sides of the fuse pad at the same time, or fill into the gap. As a result, the electrical isolation still remains.

Method for preventing burnt fuse pad from further electrical connection

The present invention provides a bump fabrication process. A wafer is provided with a patterned photoresist layer formed on the wafer. The patterned photoresist layer has a plurality of openings, corresponding to bonding pads. A conductive layer is formed on the photoresist layer and the exposed bonding pads. Afterwards, a sticker film is the provided to lift off the conductive layer on the photoresist layer, while the conductive layer within the openings is not removed. A solder paste is filled into the openings. A reflow step is performed to turn the filled solder paste into globular bumps. At last, the protoresist layer is removed.

A solder ball attaching process for attaching solder balls to a wafer is provided. First, an under-ball-metallurgy layer is formed on the active surface of the wafer. Patterned masking layers are sequentially formed over the active surface of the wafer. The masking layers together form a step opening structure that exposes the under-ball-metallic layer. A solder ball is placed on the uppermost masking layer and allowed to roll so that the solder ball drops into the step opening structure by gravity. A reflow process is conducted to join the solder ball and the under-ball-metallurgy layer together. Finally, various masking layers are removed to expose the solder ball on the bonding pad of the wafer.

Solder ball attaching process

A solder ball fabrication process for forming solder balls over a wafer having an active layer is provided. A plurality of patterned solder mask layers is sequentially formed over the active surface of the wafer. Each patterned solder mask layer has at least an opening that exposes a solder ball pad on the wafer. The opening of the patterned solder mask layers further away from the solder ball pad is larger in diameter than the opening of the patterned solder mask close to the solder ball pad. Solder material is deposited into the openings and a reflow process is conducted to melt the solder material together so that a solder ball is formed over the solder ball pad.

Solder ball fabrication process

A bump fabrication method is described. The method comprises the steps of providing a wafer having an active surface and a plurality of bonding pads formed on the active surface; respectively forming an under bump metallurgy layer onto the bonding pads, wherein the under bump metallurgy layer includes at least a wetting layer having an oxidized region and positioned at a top layer of the under bump metallurgy layer; patterning a masking layer on the active surface wherein the masking layer is provided with a plurality of openings to expose the wetting layers; removing the oxidized region of the wetting layer using ionic bombardment; fully forming a flux film on the active layer, wherein at least a portion of the flux film covers onto the wetting layer; filling a solder paste into the openings; performing a re-flow process to form a plurality of bumps after the solder paste melts so that the flux film removes the oxidized region of the wetting layer; and removing the masking layer.

Bump fabrication method

A bumping process wherein a substrate is first provided with many electrical connections. Subsequently, the bumps on the bump transfer substrate are pressed onto the electrical connections of the substrate accompanying a heating process and then the bumps are transferred onto the electrical connections of the substrate because the adhesion characteristic between the bumps and the electrical connections is better than that between the bumps and the release layer.

Bumping process

A solder paste for fabricating bumps includes a flux and metallic alloy powder. The metallic alloy powder includes a plurality of low eutectic metallic alloy granules, and the size of these metallic alloy granules is 20-60 &mgr;m and the average size of the metallic granules is 35 &mgr;m to 45 &mgr;m.

Solder paste for fabricating bump

The present invention provides a bump fabrication process. After forming an under bump metallurgy (UBM) layer and bumps in sequence over the substrate, the under bump metallurgy layer that is not covered by the bumps is etched with an etchant. The etchant mainly comprises sulfuric acid and de-ionized water. The etchant can etch the nickel-vanadium layer of the UBM layer without damaging the bumps.

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Kaohsiung, Taiwan

Yu-Chen Chou