Motorola Corporation

Analog Devices,inc.

Carl J Raleigh

Cynthia M Melton

Steven Michael Scheifers

Xiaojie Xue

Thomas M Goida

Kevin Douglas Moore

Kenneth Cholewczynski

William M Beckenbaugh

Christopher M Scanlan

William C Roman

Brian William Cousins

A lead frame packaged electronic chip. The packaged electronic chip includes a MEMS device, an integrated circuit and a wire bond electrically coupling the MEMS device and the integrated circuit. The packaged electronic chip is encased in a molding material. The packaged electronic chip further includes a mechanism that shields the wire bond and the input/output pads that couple the MEMS device and the integrated circuit from electromagnetic and radio frequency interference.

Electrical shielding in a MEMS leadframe package

A MEMS package includes a substrate having an L-shaped cross-section. The substrate includes a vertical portion having a front surface and a back surface, and a horizontal portion protruding from a lower part of the front surface of the vertical portion, wherein the front surface of the vertical portion includes a mounting region. A MEMS die is mounted on the mounting region such that the MEMS die is oriented substantially parallel to the front surface; a lid attached to the front surface of the substrate while covering the MEMS die; and a plurality of leads formed on a bottom surface of the substrate. The leads can extend substantially parallel to one another, and substantially perpendicular to the front surface. The MEMS die can be oriented substantially perpendicular to a PCB substrate on which the package is mounted.

Apparatus and method for microelectromechanical systems device packaging

A vertical mount pre-molded type package for use with a MEMS sensor may be formed with a low moisture permeable molding material that surrounds a portion of the leadframes and forms a cavity in which one or multiple dies may be held. The package includes structures to reduce package vibration, reduce die stress, increase vertical mount stability, and improve solder joint reliability. The vertical mount package includes a first leadframe having first leads and molding material substantially surrounding at least a portion of the first leads. The molding material forms a cavity for holding the MEMS sensor and forms a package mounting plane for mounting the package on a base. The cavity has a die mounting plane that is substantially non-parallel to the package mounting plane. The first leads are configured to provide electrical contacts within the cavity and to provide electrical contacts to the base.

Vertical mount package for MEMS sensors

A semiconductor device having a heat spreading layer (,) of material deposited by flame spraying on a back surface of the semiconductor die (,). The semiconductor die (,) has a thermal coefficient of expansion substantially similar to the thermal coefficient of expansion of the flame sprayed material. The flame sprayed material may be deposited directly on the semiconductor die (,) or on a backmetal layer (,). The heat spreading layer (,) is suitable for affixing the semiconductor die (,) to a metal substrate (,).

Semiconductor device with flame sprayed heat spreading layer and method

A hybrid multi-chip module includes semiconductor chips (27, 31) bonded to a base plate (24). The base plate includes a substrate (11) having two surfaces (12, 13) and a conductive material (16) molded on the two surfaces (12, 13). A coefficient of thermal expansion (CTE) mismatch between the substrate (11) and the conductive material (16) at the first surface (12) is balanced by a similar, but opposite, CTE mismatch between the substrate (11) and the conductive material (16) at the second surface (13). The CTE mismatch balance across the base plate (24) produces a base plate (24) having a substantially planar form at high temperatures.

Semiconductor device balancing thermal expansion coefficient mismatch

An integrated circuit component is attached to a printed circuit board by solder bump interconnections that are formed between metal bumps on the component and a metal-plated terminal on the board. The metal plate overlies both a bond pad and an adjacent runner of each terminal and is formed of a first metal, which is preferably a tin-base alloy. The metal bumps on the component are formed of a second metal, which is preferably an indium-base alloy. The component and board are assembled and heated to a temperature less than the melting temperatures of the first and second metals. At the interface between the bumps and the plate, the first and second metals cooperate to form a liquid phase which, upon cooling and solidifying, completes the interconnection.

Low temperature method for forming solder bump interconnections to a

An improved electrical component package comprises a component attached to a substrate by a plurality of multisolder interconnections. Each interconnection comprises a preformed spacer bump composed of a first solder alloy, preferably a lead-base tin alloy containing greater than 90 weight percent lead. The spacer bump is directly metallurgically bonded to a metallic electrical contact of the component and rests against a corresponding metallic electrical contact of the substrate, but is not bonded thereto. Each interconnection further comprises a sheath portion formed of a second compositionally distinct solder alloy having a liquidus temperature less than the first alloy solidus temperature. A preferred second solder is a tin-lead alloy comprising between about 30 and 50 weight percent lead and the balance tin or indium. The sheath is bonded to the spacer bump and to the substrate contact to complete attachment of the component to the substrate and preferably extends to the component contact, encasing the bump, to produce an interconnection having an hour glass configuration to reduce thermal fatigue stresses at the solder bonds to the contacts.

Noncollapsing multisolder interconnection

A method for attaching an integrated circuit component to a printed circuit board by a plurality of solder bump interconnections utilizes a printed circuit board comprising a solder-plated circuit trace. The trace includes terminals, each including a terminal pad and a runner section. A solder plate formed of a first solder alloy is applied to the terminal to extend continuously between the pad and the runner section. Solder bumps are affixed to the component and are formed of second compositionally distinct solder alloy having a melting temperature greater than the first alloy. The component and board are then assembled so that the bumps rest against the solder-plated terminal pads, and heated to a temperature effective to melt the solder plate but not the bump alloy. Upon cooling to resolidify the solder, the solder plate is fused to the bumps to form the interconnections.

Method for forming solder bump interconnections to a solder-plated

An improved electrical component package comprises a component attached to a substrate by a plurality of multisolder interconnections. Each interconnection comprises a preformed spacer bump composed of a first solder alloy, preferably a lead-base tin alloy containing greater than 90 weight percent lead. The spacer bump is bonded to a metallic electrical contact of the component and rests against a corresponding metallic electrical contact of the substrate, but is not directly metallurgically bonded thereto. Each interconnection further comprises a sheath portion formed of a second compositionally distinct solder alloy having a liquidus temperature less than the first alloy solidus temperature. A preferred second solder is a tin-lead alloy comprising between about 30 and 50 weight percent lead and the balance tin or indium. The sheath is bonded to the spacer bump and to the substrate contact to complete attachment of the component to the substrate and preferably extends to the component contact, encasing the bump, to produce an interconnection having an hour glass configuration to reduce thermal fatigue stresses at the solder bonds to the contacts. A method for forming the multisolder interconnection is presented wherein the sheath is derived from a solder microball situated on the substrate contact in juxtaposition to the spacer bump for reflow.

A body formed of a lead-tin solder alloy is pretreated to deposit palladium thereon prior to soldering to a metallic substrate. It is found that the palladium deposit enhances wetting of the substrate by the solder liquid during reflow and thereby, upon cooling, produces a strong metallurgical bond. In a preferred embodiment, lead-tin solder balls are pretreated by applying tin-palladium colloidal particles and dissociating the particles to form a discontinuous metallic palladium deposit.

Growing community of inventors

Cary, IL, United States of America

Carl J Raleigh