Motorola Corporation

Frank J Juskey, Jr

Anthony B Suppelsa

Barry M Miles

Bruce J Freyman

Douglas W Hendricks

Robert W Pennisi

Dale W Dorinski

Lonnie L Bernardoni

Marc V Papageorge

Thomas J Swirbel

Glenn F Urbish

Anthony J Suppelsa

Kingshuk Banerji

Joaquin Barreto

Fadia Nounou

Robert Thomas Carson

Jill L Flaugher

Kenneth M Wasko

Glenn E Gold

Arnold W Hogrefe

Keith D Soldner

Juan O Alfonso

Linda K Berrian

Sally A Stallings

A process (200) for fabricating a flex circuit (708, 806, 812, 818 or 824) using a fabrication process without the use of a photomask includes the steps of generating (412) an electronic image (702 or 802) of circuit traces (704 or 804) representing at least a single-sided flex circuit, and selectively thermal transferring (506 or 606) a resin to either a conductively clad or non-conductive flexible substrate (304) under the control of the electronic image (702 or 802) to form either an etch resist or a conductor which defines the circuit traces (704 or 804). The conductively clad flexible substrate (304) is etched to form the circuit traces (704 or 804) of the flex circuit defined by the etch resist, after which the etch resist is removed.

Process for fabricating flex circuits and product thereby

A method of making a transfer molded chip carrier. A semiconductor device (10) is first electrically and mechanically attached to a substrate (12). The substrate (12) is then treated by sputter etching so that it will provide good adhesion between the substrate and a molding compound (18) that is subsequently molded to the substrate (25). Portions of the treated substrate are then selectively contaminated in order to reduce the adhesion between these selected portions of the substrate and the molding compound. The molding compound is then formed around the semiconductor device so as to encapsulate it and also part of the surface of the substrate. Portions (20) of the transfer molded material that were molded over the selectively contaminated portions of the substrate (12) are then removed by breaking away.

Method of selectively releasing plastic molding material from a surface

A semiconductor device package comprises an integrated circuit chip (10), a substrate (16), an encapsulant (30), and an organic coupling agent or underfill material (12) disposed between the integrated circuit chip and the first side of the substrate. The chip has a plurality of interconnection pads (14) disposed on an active surface of the chip at some minimum spacing 'X.' Each of the interconnect pads also has electrically conducting bumps (26) on them. The substrate has a circuit pattern (20) on a first side and an array of solder pads (23) spaced a certain distance apart on an opposite side of the substrate. The distance between these pads is greater than the minimum distance (X) between the interconnect pads on the IC. The circuit pattern is electrically connected to the array of solder pads by plated through holes (22). The length and width of the circuit carrying substrate is substantially greater than the length and width of the integrated circuit chip. The chip is mounted face down to the substrate with the electrically connecting bumps, such that at least some of the plated through holes in the substrate are covered by the chip. The polymeric encapsulant (30) covers the entire chip and substantially all of the first side of the substrate, providing a sealed package.

Leadless integrated circuit package

A conductive adhesive (120) for electrically and mechanically bonding circuit terminals (105) includes a polymer (121) having a predetermined curing temperature range, a first conductive particulate material (125) suspendable in the polymer (121) for providing substantially uniform conductivity throughout the conductive adhesive (120), and a second conductive particulate material (130) suspendable in the polymer (121) for metallurgically bonding together particles of the first particulate material (125). The first conductive particulate material (125) provides substantially uniform conductivity throughout the conductive adhesive (120) and includes metallic particles having a melting point above the curing temperature of the polymer. The second conductive particulate material (130) welds together particles of the first particulate material (125) and includes metallic particles having a melting point within the curing temperature range of the polymer (121).

Electrically conductive adhesive

A multichip circuit package is formed for use with an EPROM chip. The active circuitry on the EPROM die surface is revealed. An EPROM die (14) is mounted on an insulating substrate (10). The active circuitry (15) on the die is connected to a conductive circuit pattern (13) on the substrate by wire bonds (16) between the die and the conductive circuit pattern. A second integrated circuit die (20) is also mounted on the substrate and electrically connected to the conductive circuit pattern by wire bonds. A plastic material (50) is then molded to encapsulate the perimeter (18) of the EPROM and the associated thin wires, the entire second integrated circuit die and it's associated thin wires, at least a portion of the conductive circuit pattern, and portions of the insulating substrate. The plastic material is formed so as to expose the active circuitry on the face of the EPROM.

Light erasable multichip module

A semiconductor device package comprises a substrate (10), a flip-chip (16), an underfill adhesive (25), and a thermally and electrically conductive plastic material (20). A leadless circuit carrying substrate has a metallization pattern (13) on a first side (15), one portion of the metallization pattern being a circuit ground (17). The second side has an array of surface mount solder pads (24) electrically connected to the metallization pattern by means of at least one conductive via (26) through the substrate. A semiconductor device (16) is flip-chip mounted to the metallization pattern by means of metal bumps (22). An underfill adhesive (25) fills the gap between the semiconductor device and the substrate. A thermally and electrically conductive plastic material (20) containing metal particles is transfer molded to encapsulate the semiconductor device, the underfill adhesive, and a portion of the first side of the leadless circuit carrying substrate, forming a cover. The conductive plastic material is electrically connected to the circuit ground to shield the semiconductor device from radio frequency energy, and is mechanically attached to the semiconductor device to dissipate heat. Fins (28) may be molded into the conductive plastic material to further enhance the ability to dissipate heat.

Thermally conductive integrated circuit package with radio frequency

A flow formed encapsulated integrated circuit package (100) includes a printed circuit substrate (160) having upper and lower opposed surfaces and one or more anchor holes (150). The one or more anchor holes (150) have an upper aperture in the upper surface and a lower aperture in the lower surface. One or more integrated circuit die (130) are electrically and mechanically attached to the upper surface of the substrate (160). In addition, a solder resist mask (190) is attached to the lower surface of the substrate which covers the aperture of the one or more anchor holes (150). Flow formed material (110) is formed around the integrated circuit die (130) so as to encapsulate the one or more integrated circuits (150), the flow formed material (110) covering at a least a portion of the upper surface of the printed circuit substrate (160) and extending substantially into the anchor hole (150).

Anchoring method for flow formed integrated circuit covers

An encapsulated electronic package (10) is made by bonding one or more semiconductor devices or integrated circuits (16) to a printed circuit board with an adhesive (14), and covering with a glob top encapsulant (15). The printed circuit board has a metal circuit pattern (12) on one side, and, optionally, solder pads (27) on the second side. The glob top encapsulant covers the integrated circuit, portions of the metal circuit pattern, and portions of the printed circuit board surface. The printed circuit board, the adhesive, and the encapsulant are all made from the same type of resin. In the preferred embodiment of the invention, the resin used to make the printed circuit board, the adhesive, and the encapsulant is an organosilicon polymer comprised substantially of alternating polycyclic hydrocarbon residues and cyclic polysiloxane or siloxysilane residues linked through carbon-silicon bonds.

Encapsulated electronic package

An integrated circuit package (10) comprises a semiconductor die (14) having a top surface and a bottom surface, and a substrate (16) for receiving the semiconductor die. The substrate should have an aperture(s) (18) below the semiconductor die for providing moisture relief during temperature excursions. An adhesive (20) applied to the substrate allows for mounting the semiconductor die to the substrate. Then, the semiconductor die is wirebonded to the substrate. Finally, an encapsulant (12) for sealing the top surface of the semiconductor die is formed over the semiconductor die and portions of the substrate.

Moisture relief for chip carrier

A fluxing composition for soldering metals together, contains a carrier solvent, an oxide removing agent, and a nitrogen liberating compound. The oxide removing agent sublimes at or below the temperature at which the metals are soldered together. The nitrogen liberating compound sublimes or decomposes at below the temperature at which the metals are soldered together in order to provide a blanket of inert gas over the metals being soldered. The oxide removing agent is 2-amino-isophthalic acid, 5-amino-isophthalic acid, isophthalic acid, ammonium fluoborate, or ammonium salicylate. The compound that liberates nitrogen upon heating is 1,2-benz-3,4-anthraquinone, 1,2-benz-9,10-anthraquinone, 5,6-chrysoquinone, 6,12-chrysoquinone, 2,3-benzanthraquinone, 2-amino-isophthalic acid, 5-amino-isophthalic acid, or 5-isoquinoline carboxylonitrile. Electronic components are soldered to a circuit board by applying the fluxing composition to the circuit board. The fluxing composition, the component and the circuit board are heated to a temperature sufficient to cause the activator to react with metal oxides on either the component or the circuit board and to sublime, and also to a temperature to cause the nitrogen containing compound to decompose or sublime.

Subliming solder flux composition

A three-dimensional printed circuit assembly is formed by first making a substrate (20). A substrate (20) is first formed from a photoactive polymer (14) that is capable of altering its physical state when exposed to a radiant beam (30). At this point, the substrate is only partially cured. A conductive circuit pattern (50) is then formed on the partially cured substrate. The substrate is then molded to create a three-dimensional structure, and then further cured to cause the photoactive polymer to harden.

Method of forming a three-dimensional printed circuit assembly

A non-hardening, solvent removable hydrophobic conformal coating is provided for electronic devices, such as printed circuit boards. The coating material comprises a metal alkyl benzyl sulfonate, together with a carrier and a solvent. The metal alkyl benzyl sulfonate may include compounds such as calcium eicosanylbenzyl sulfonate. The carrier may be any oxidized hydrocarbon, such as lauryl ethanoxylate, for example, and the solvent may be any low boiling aliphatic hydrocarbon. Though the coating is impervious to water, it may be readily and selectively removed using a small quantity of a non-polar organic solvent, such as mineral spirits or terpenes. Thus, although the electronic device is protected from corrosion, electromigration and physical harm by the coating, the coating may be easily, quickly and selectively removed in the event a component needs replacement, repair or adjustment.

Non-hardening solvent removable hydrophobic conformal coatings

A method of making a pad array chip carrier package is disclosed. A semiconductor device (10) is bonded to a ceramic substrate (12). The semiconductor device may be attached to the substrate by wirebonding, tab bonding or flip chip bonding. The bonded assembly (16) is then attached to a flexible temporary support substrate (18) by means of an adhesive (19). The entire assembly is then placed into a mold cavity (20 and 22) and registered against the temporary support substrate (18). Plastic material (30) is molded about the semiconductor device and associated wirebonds in order to encapsulate the device. After removal from the mold, the encapsulated assembly is removed from the temporary support substrate (18) by peeling the temporary support substrate (18) from the circuit substrate.

Method of making a transfer molded semiconductor device

An electronic package, comprising a circuit carrying substrate (30) and a semiconductor device (35). The substrate (30) has two opposing surfaces, the first or bottom surface having a plurality of solder pads (31) and the second or top surface having a circuitry pattern defined on it. A semiconductor device (35) is attached to the top surface of the circuit carrying substrate (30). A molded body (33) is formed completely around the semiconductor device (35) in order to encapsulate it, the molded body also substantially covering the top surface of the circuit carrying substrate (30). A layer of metal deposited directly on the molded body and the top surface of the circuit carrying substrate is delineated into another conductive circuitry pattern (38), with part of the pattern (36) connected to the circuitry pattern on the circuit carrying substrate. An electronic component (32) is mounted on the molded body (33) and electrically connected to the conductive circuitry pattern (38).

Multicomponent integrated circuit package

An integrated circuit package (10) is formed to reveal the active circuitry (15) on the die surface. An integrated circuit die (12) is mounted on a die mounting portion (32) of a metal lead frame (30) in such a manner that the die is supported on the lead frame by the perimeter portion of the die. The active circuitry (15) on the die is connected to the various metal frame leads (33) by wire bonds (18) between the bond pads on the die and the metal lead frame. Plastic molding material (50) is then molded to encapsulate the wire bond pads (17), the perimeter of the integrated circuit die (16), the wire bonds (18), a portion of the leads (33), the perimeter portion of the back of the die (22), and the lead frame die mounting portion (32). The plastic material is formed so as to expose the active circuitry on the face of the die and a central portion on the back of the die.

Growing community of inventors

Coral Springs, FL, United States of America

Frank J Juskey, Jr