Intel Corporation

Georgia Tech Research Corporation

Song-Hua Shi

Tian-An Chen

Lejun Wang

Milan Djukic

Ching-Ping Wong

Carlos A Gonzalez

Bob Sankman

Jason Jieping Zhang

Katrina Certeza

High yield, high reliability, flip-chip integrated circuit (IC) packages are achieved utilizing a combination of heat and pressure to bond flip-chip die and to cure no-flow underfill material. The underfill comprises a filler or low coefficient of thermal expansion (CTE) material to decrease CTE of the cured underfill. The filler material can be selected from the group comprising silica, silicon oxide, silicon dioxide, silicon nitride, aluminum oxide, aluminum nitride, or a mixture thereof. The filler material may also increase the viscosity of the uncured underfill and/or increase the modulus of elasticity of the cured underfill. In some method embodiments, a thermocompression bonder is used to simultaneously provide solder bump reflow and underfill curing. Application of various methods to a component package, an electronic assembly, and an electronic system are also described.

Electronic assemblies and systems with filled no-flow underfill

A system for underfilling in a chip package includes an underfill mixture that ameliorates the CTE mismatch that typically exists between a packaged die and a resin-impregnated fiberglass mounting substrate. In one embodiment, the system includes an underfill mixture that alone exhibits a CTE that is characteristic of an inorganic-filled underfill composite previously known. An embodiment is also directed to the assembly of a flip-chip package that uses an underfill mixture.

Flip-chip system and method of making same

A temperature sustaining flip chip process in which ILD cracking and delamination are lessened. A sequence of substrate prebake, underfill dispense, chip placement, solder reflow and underfill cure operative stages introduces lower thermal-mechanical stress during flip chip packaging.

Temperature sustaining flip chip assembly process

Electronic assemblies with filled no-flow underfill

An electronic structure includes an electronic device coupled to a substrate by conductive bumps and ball limiting metallurgy (BLM). Underfill material having filler particles is disposed in a space between the electronic device and the substrate. A weight percentage of the filler particles is at least about 60%. A particle size of at least 90 wt % of the filler particles is less than about 2 &#x3bc;m and/or the filler particles are coated by an organic coupling agent. Once the underfill material is fully cured, its coefficient of thermal expansion is no more than 30 PPM/&#xb0; C., and its glass transition temperature is at least 100&#xb0; C., and its adhesion to a passivation layer of the electronic device, to the substrate and to the electronic device at its edges is such that the electronic structure passes standardized reliability tests without delamination of the ball limiting metallurgy.

Underfill material to reduce ball limiting metallurgy delamination and cracking potential in semiconductor devices

Microelectronic and optoelectronic packaging embodiments are described with underfill materials including polybenzoxazine, having the general formula: 

Microelectronic or optoelectronic package having a polybenzoxazine-based film as an underfill material

A heater for flip chip bonding transfers more heat to the periphery of a die than to the center. This may result in a more even temperature profile along the die and may help prevent epoxy voiding problems.

Chip bonding heater with differential heat transfer

A guided heating apparatus and a method for using the same is provided. The apparatus includes a guiding enclosure, a supporting piece, and an absorbing piece. The guiding enclosure guides and keeps energy from an energy source within the guiding enclosure. The guiding enclosure is made of a material reflective of the energy. The energy source is either one of a microwave source and an infrared source. The supporting piece is detachably coupled with the guiding enclosure and is made of a material transparent to the energy. The absorbing piece is coupled to and supported by the supporting piece within the guiding enclosure. The absorbing piece is made of at least one material that absorbs the energy and transfers the energy to an object to be heated. The absorbing piece has a predetermined composition that controls an energy absorption rate of the absorbing piece.

Guided heating apparatus and method for using the same

The invention provides a heater for flip chip bonding. The heater transfers more heat to the periphery of a die than to the center. This results in a more even temperature profile along the die and helps prevent epoxy voiding problems.

Microelectronic and optoelectronic packaging embodiments are described with underfill materials including polybenzoxazine, having the general formula:

A siloxirane based no-flow underfill material is provided. The material has a low coefficient of thermal expansion, low moisture uptake and a high distortion temperature. The material typically includes at least an epoxy siloxiane resin, a cross-linking hardener, a catalyst, and a fluxing agent.

No-flow underfill material

The present invention provides a novel process and its required fluxable materials for building low-cost flip-chip interconnect structures. The novel process involves two fluxable materials, fluxable wafer-level compressive-flow underfill material (WLCFU) and fluxable tacky film, and applies these two materials on a wafer level. The two materials can provide sufficient fluxing capability during solder reflow and significant improvement of the fatigue life of the formed solder interconnects after fully cured.

Process and material for low-cost flip-chip solder interconnect structures

A polybenzoxazine based wafer-level underfill material. The material may be provided to a surface of a semiconductor wafer. The semiconductor wafer may then be sawed into individual chips. The polybenzoxazine based underfill material may be for use between a chip and a package substrate.

Growing community of inventors

Phoenix, AZ, United States of America

Song-Hua Shi