Texas Instruments Corporation

Edgardo R Hortaleza

Willmar E Subido

Orlando F Torres

Lei Li

Stuart M Jacobsen

Timothy J Hogan

The invention provides methods and systems for laser assisted wirebonding. One or more conditioning laser pulses are used to prepare a bonding surface for wirebonding by removing impurities such as residues from manufacturing processes, oxides, or irregularities on the bonding surface. Subsequently, a free air ball is brought into contact with the conditioned bonding surface to form a weld.

Methods and systems for laser assisted wirebonding

A metal structure for an integrated circuit, which has copper interconnecting metallization () protected by an overcoat layer (). A portion of the metallization is exposed in a window () opened through the thickness of the overcoat layer. The metal structure comprises a patterned conductive barrier layer () positioned on the copper metallization, wherein this barrier layer forms a trough with walls () conformal with the overcoat window. The height () of the wall is less (between 3 and 20 %) than the overcoat thickness (), forming a step (). A plug () of bondable metal, preferably aluminum, is positioned in the trough and has a thickness equal to the trough wall height ().

Structure and method for contact pads having a recessed bondable metal plug over of copper-metallized integrated circuits

An integrated circuit having copper interconnecting metallization () protected by a first, inorganic overcoat layer (), portions of the metallization exposed in windows () opened through the thickness of the first overcoat layer. A patterned conductive barrier layer () is positioned on the exposed portion of the copper metallization and on portions of the first overcoat layer surrounding the window. A bondable metal layer () is positioned on the barrier layer; the thickness of this bondable layer is suitable for wire bonding. A second, organic overcoat layer () is surrounding the window so that the surface () of this second overcoat layer at the edge of the window is at or above the surface () of the bondable layer. The second overcoat layer may be spaced () from the edge of the bondable metal layer.

Structure and method for contact pads having a protected bondable metal plug over copper-metallized integrated circuits

A method ( ) of fabricating a micromechanical device ( ) by performing spacer layer undercutting ( ) and passivation at the package level. A back-end assembly process utilizes a full-cut saw process to separate the partially fabricated micromechanical devices. The individual die are then attached by pick and place equipment to a lead frame and are wire bonded, before the die are undercut. This technique avoids the generation of any particles from becoming lodged under movable structure during the cut process, and further, reduces the susceptibility of the die to damage or particles generated during the pick and place process.

Undercut process with isotropic plasma etching at package level

A heat dissipating flip-chip Ball Grid Array (BGA) ( ) including a substrate ( ), a die ( ), a first set of solder balls ( ) coupling the die with the substrate, a thermal compound ( ) attached to a backside of the die, a second set of solder balls ( ) attached to the substrate, and a printed circuit board ( ) that includes a heat dissipating metal ( ). The heat dissipating metal is in contact with the thermal compound, and the second set of solder balls is connected to thermal vias in the printed circuit board.

Heat dissipating flip-chip ball grid array

A method of bonding wire between at least one pair of bond locations in a semiconductor device and the bonder. A conveyor is provided having a conveying surface for conveying in a predetermined direction a partially fabricated semiconductor device having first and second bonding locations. A first capillary is provided for forming a stitch bond to the first bonding location, the first capillary being disposed at an angle of about 45 degrees with respect to the predetermined direction and a line normal thereto and substantially parallel to the plane of the conveying surface. A stitch bond is formed on the first bonding location with the first capillary. The first capillary is at an angle of substantially 45 degrees with respect to a line normal to the plane of the conveying surface. A second capillary is provided for forming a stitch bond to the second bonding location, the second capillary being disposed at an angle of about 45 degrees with respect to the predetermined direction and a line normal to the predetermined direction and substantially parallel to the plane of the conveying surface and a stitch bond is formed on the second bonding location with the second capillary. The second capillary is at an angle of substantially 45 degrees with respect to a line normal to the plane of the conveying surface. The first and second capillaries are disposed at an angle of about 90 degrees with respect to each other with respect to each other in a direction normal to said plane.

Angled transducer-dual head bonder for optimum ultrasonic power application and flexibility for tight pitch leadframe

A method of bonding wire and the bonder which includes providing a wire bonder for bonding wire to a bonding location. The wire bonder has a first bonding head designed to form a stitch bond while travelling in a first predetermined direction, the first bonding head having a first major axis and a first minor axis normal to the first major axis, the first major axis being at an angle of from about 45 degrees to a finite angle greater than zero relative to the first predetermined direction and a second bonding head designed to form a stitch bond while travelling in a second predetermined direction, the second bonding head having a second major axis and a second minor axis normal to the second major axis, the second major axis being at an angle of from about 45 degrees to a finite angle greater than zero relative to the second predetermined direction. An area having bonding locations to which the bonder is to make wire bonds is divided into a plurality of regions. Then the first bonding head is caused to make wire bonds in a predetermined one of the plurality of regions and the second bonding head is caused to make wire bonds in a predetermined second one of the plurality of regions. The first major axis is preferably at an angle of about 45 degrees with respect to the first predetermined direction and the second major axis is preferably at an angle of about 45 degrees with respect to the second predetermined direction. The first predetermined direction is preferably substantially normal to the second predetermined direction.

Balancing of x and y axis bonding by 45 degree capillary positioning

Angled transducer-dual head bonder for optimum ultrasonic power

An apparatus (304) and method is provided for bonding wire (104) to bond sites (108) of integrated circuits (110), lead frames, and packages at room temperatures. In preferred embodiments a ball end (106) of a gold wire (104) is bonded to an aluminum bond pad (108). Apparatus (304) includes a high frequency ultrasonic energy source (306) designed to provide ultrasonic energy at frequencies above 200 kHz. The ultrasonic energy is transmitted to the bonding interface via capillary (302). In this manner, a strong bond is formed between ball end (106) and bonding site (108). The apparatus and method provided enable bonds of sufficient shear strength to be fabricated in a sufficiently short bonding time even at ambient temperatures, enabling the efficient fabrication of temperature sensitive devices such as micromechanical structures.

Room temperature ball bonding

A method of bonding a wire between a semiconductor die pad and a lead finger of a lead frame which includes providing a capillary having a bore and a wire pigtail extending through the bore and externally of the capillary. A ball is formed with the pigtail, a semiconductor die pad is provided and a ball bond is formed on the die pad with the ball. A lead frame finger is provided and the capillary and the wire threaded through the bore are moved to the lead frame finger. A stitch bond is formed on the lead finger with the capillary. The capillary is moved from the stitch bond with a pigtail of the wire extending out of the bore of the capillary. A second ball is formed with the pigtail and the capillary is again moved toward the stitch bond until the second ball contacts the stitch bond. A ball bond is then formed over and secured to the stitch bond and to the lead frame finger. The wire is preferably a gold alloy and the wire bond location includes a copper trace adhered to a flexible electrically insulating film.

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Garland, TX, United States of America

Edgardo R Hortaleza