Micron Technology Incorporated

Ed A Schrock

Tongbi T Jiang

Alan G Wood

Ford B Grigg

Warren M Farnworth

Chad A Cobbley

John E Vannortwick

Several embodiments of the present technology are described with reference to a semiconductor apparatus. In some embodiments of the present technology, a semiconductor apparatus includes a stack of semiconductor dies attached to a thermal transfer structure. The thermal transfer structure conducts heat away from the stack of semiconductor dies. Additionally, the assembly can include molded walls to support the thermal transfer structure.

Thermal transfer structures for semiconductor die assemblies

Several embodiments of the present technology are described with reference to a semiconductor die assembly and processes for manufacturing the assembly. In some embodiments of the present technology, a semiconductor die assembly includes a stack of semiconductor dies attached to a thermal transfer structure (also known as a 'heat spreader,' 'lid,' or &#x201c;thermal lid&#x201d;). The thermal transfer structure conducts heat away from the stack of semiconductor dies. Additionally, the assembly can include molded walls fabricated with molding material to support the thermal transfer structure.

Methods of forming microelectronic device wafers include fabricating a plurality of semiconductor dies at an active side of a semiconductor wafer, depositing a mask on the semiconductor wafer, removing a central portion of the mask and the semiconductor wafer, and etching. The semiconductor wafer has an outer perimeter edge and a backside that is spaced from the active side by a first thickness. The mask is deposited on the backside of the semiconductor wafer and has a face that is spaced from the backside by a mask thickness. The thinned portion has a thinned surface that is spaced from the active side by a second thickness that is less than the first thickness, and the thinned surface is etched.

Microelectronic device wafers and methods of manufacturing

A plurality of lead frames is supplied in a lead frame-by-lead frame sequence. A curable adhesive, preferably a 505 Epoxy, is applied to one surface of each lead frame as it indexes through an application device. An attaching device attaches a device to each lead frame with the adhesive by holding the device in place to cure for a preselected period of time of about one second. Later, the lead frames have their edges trimmed and then are separated into separate lead frames.

Methods for epoxy loc die attachment

A method for attaching a workpiece, for example a semiconductor die, to a workpiece holder, for example a lead frame die support, comprises the steps of interposing an uncured adhesive between the semiconductor die and the die support and preheating the adhesive from an ambient temperature to a preheat temperature of between about 150&#xb0; C. and about 160&#xb0; C. over a period of about 1.5 seconds. Next, the preheat temperature is maintained for about 1.5 seconds, then the adhesive is further heated to a temperature of between about 190&#xb0; C. and about 200&#xb0; C. over a period of about 1.0 second. The inventive method quickly cures the adhesive to secure the die to the support with acceptably low levels of voiding. An apparatus which can be adapted to perform the inventive method is further described.

Method and apparatus for attaching a workpiece to a workpiece support

Method and apparatus for epoxy LOC die attachment

A plurality of lead frames is supplied in lead frame by lead frame sequence. A curable adhesive, preferably a 505 Epoxy, is applied to one surface of each lead frame as it indexes through an application device. An attaching device attaches a device to each lead frame with the adhesive by holding the device in place to cure for a preselected period of time of about one second. Later, the lead frames have their edges trimmed and then are separated into separate lead frames.

Method and apparatus for epoxy loc die attachment

A plurality of lead frames is supplied in a lead frame-by-frame sequence. A curable adhesive, preferably a 505 Epoxy, is applied to one surface of each lead frame as it indexes through an application device. An attaching device attaches a semiconductor device to each lead frame with the adhesive by holding the semiconductor device in place to cure for a preselected period of time of about one second. Later, the lead frames have their edges trimmed and then are separated into separate lead frames.

Apparatus for epoxy loc die attachment

A method for attaching a workpiece, for example a semiconductor die, to a workpiece holder, for example a lead frame die support, comprises the steps of interposing an uncured adhesive between the semiconductor die and the die support and preheating the adhesive from an ambient temperature to a preheat temperature of between about 150&deg; C. and about 160&deg; C. over a period of about 1.5 seconds. Next, the preheat temperature is maintained for about 1.5 seconds, then the adhesive is further heated to a temperature of between about 190&deg; C. and about 200&deg; C. over a period of about 1.0 second. The inventive method quickly cures the adhesive to secure the die to the support with acceptably low levels of voiding. An apparatus which can be adapted to perform the inventive method is further described.

A plurality of lead frames is supplied in frame by frame sequence. A curable adhesive, preferably a 505 Epoxy, is applied to one surface of each lead frame as it indexes through an application device. An attaching device attaches a device and holds it during in place to cure for a preselected period of time of about one second to each device site with adhesive. Later, the lead frames have their edges trimmed and then are separated into separate lead frames.

A method for attaching a semiconductor die to a leadframe is provided. Also provided are an improved semiconductor package, and a system for performing the method. The method includes applying an instant curing adhesive, such as a cyanoacrylate monomer or anaerobic adhesive, to the leadframe or die, and then polymerizing the adhesive at room temperature and ambient atmosphere, to form a cured adhesive layer between the die and lead frame. A catalyst can be applied to the leadframe, to the die or to the adhesive, to initiate polymerization. In addition, fillers can be added to the adhesive to improve various electrical and physical characteristics of the resultant adhesive layer. The system includes a dispensing mechanism for dispensing the instant curing adhesive on the leadframe or die, and a die attach mechanism for positioning and placing the die in contact with the dispensed adhesive.

Semiconductor die attachment method and apparatus

A method for attaching bumped semiconductor dice to substrates, such as printed circuit boards and multi chip modules, is provided. The method includes the steps of: providing an instant curing adhesive formulated to cure within 0.25 to 60 seconds, and dispensing a volume of the adhesive onto the substrate. The method also includes the steps of heating the die, and aligning the contact bumps on the die to the contacts on the substrate. Following these steps the die can be brought into contact with the substrate to form an adhesive layer therebetween. Heat from the die cures the adhesive layer. In addition, the cured adhesive layer tensions the die against the substrate, and compresses the contact bumps and contacts to form low resistance electrical connections. A system for performing the method includes a lead-on-chip die attacher configured to heat the die, to dispense the adhesive, to align the die and substrate, and then to press the die against the substrate with a desired pressure.

Method and system for attaching semiconductor dice to substrates

A method for attaching a workpiece, for example a semiconductor die, to a workpiece holder, for example a lead frame die support, comprises the steps of interposing an uncured adhesive between the semiconductor die and the die support and preheating the adhesive from an ambient temperature to a preheat temperature of between about 150.degree. C. and about 160.degree. C. over a period of about 1.5 seconds. Next, the preheat temperature is maintained for about 1.5 seconds, then the adhesive is further heated to a temperature of between about 190.degree. C. and about 200.degree. C. over a period of about 1.0 second. The inventive method quickly cures the adhesive to secure the die to the support with acceptably low levels of voiding. An apparatus which can be adapted to perform the inventive method is further described.

Growing community of inventors

Boise, ID, United States of America

Ed A Schrock