Delco Electronics Corporation

Ralph Edward Cornell

William David Higdon

Shing Yeh

Christine Ann Paszkiet

Christine Redder Coapman

Curt A Erickson

Aparna Vaidyanthan

Susan Acheson Mack

A surface mount circuit device (,), such as a flip chip, of the type which is attached to a conductor pattern (,) with solder bump connections (,). The solder bump connections (,) are formed by reflowing solder on shaped input/output pads (,) on the device (,), with the shape of the pads (,) being tailored to favorably affect optimal distribution, shape and height of the solder bump connections (,) following reflow soldering of the device (,) to the conductor pattern (,). The solder bump connections (,) are preferably characterized by a shape that increases the stand-off height of the device (,). The shaped solder bump connections (,) also promote stress relief during thermal cycling, improve mechanical bonding, allow better penetration of cleaning solutions, and improve flow of encapsulation materials between the device (,) and its substrate (,).

Solder bump input/output pad for a surface mount circuit device

A conductor (112) and method for attaching a surface mount device to the conductor (112), in which solder bumps (16) formed by the method are characterized as being accurately located on the conductor (112) and having a bump height and shape that provides stress relief during thermal cycles, minimizes bridging between adjacent bumps (16), allows penetration of cleaning solutions for removing undesirable residues, and enables the penetration of mechanical bonding and encapsulation materials between the chip and its substrate (10). Such benefits are achieved by forming the conductor (112) of a nonsolderable material, on which a solderable pillar (114) is formed. The pillar (114) is selectively formed to have a shape that determines the distribution and height of the solder bump (16) on the conductor (112).

Method for controlling solder bump shape and stand-off height

A carrier device (10) is provided for transferring solder bumps (16) to a surface of a flip chip integrated circuit device (18). The carrier device (10) is equipped with cavities (12) on its surface for receiving and retaining solder material (14), by which the solder material (14) can be transferred to the flip chip (18) as molten solder bumps (16). The cavities (12) are located on the surface of the carrier device (10) such that the location of the solder material (14) will correspond to the desired solder bump locations on the flip chip (18) when the carrier device (10) is registered with the flip chip (18). The size of the cavities (12) can be controlled in order to deliver a precise quantity of solder material (14) to the flip chip (18).

Solder bump transfer device for flip chip integrated circuit devices

A flip chip integrated circuit device (110) is provided having a surface, a perimeter, and solder bumps (112) located on the surface. At least one solder bump (112), and preferably a plurality of solder bumps (112), are spaced apart from the perimeter of the device (110). Electrically conductive runners (118) extend from the perimeter of the device (110) to each of those solder bumps (112) that are spaced apart from the perimeter, so as to electrically interconnect the solder bumps (112) to a point, such as a pad (116), at the perimeter. As a result, not all of the solder bumps (112) employed by the device (110) need be accommodated at the perimeter of the device (110), such that the size and number of the solder bumps (112) does not dictate the size of the device (110).

Growing community of inventors

Kokomo, IN, United States of America

Ralph Edward Cornell