International Business Machines Corporation

Harold Kohn

Kishor V Desai

Charles Gerard Woychik

Robert H Katyl

Vilakkudi G Veeraraghavan

Nelson P Franchak

Tamar A Sholtes

Voya Rista Markovich

David John Russell

Donald P Seraphim

David Erle Houser

Thomas P Duffy

George J Saxenmeyer, Jr

Donald J Lazzarini

Reinhold E Tomek

James R Webb

Richard C Senger

James M Ergler

Ronald J Romanosky

Gordon L Williams

Michael Smetana

Endwell

A modular structure for providing electrical interconnections achieves greatly increased wiring density by forming vias and wiring patterns by chemical (e.g. lithographic) processes rather than by mechanical processes such as punching of vias and screening patterns of conductive paste. A basic module is a power core comprising an apertured metallic foil with an insulator applied to surfaces thereof, extending through at least one aperture and exposing the metallic foil in at least one aperture. The foil in the power core provides stiffness to facilitate subsequent handling and electrical shielding between conductive layers as well as a potential power connection. Via connections of increased conductivity and robustness are formed by plating the interior of vias after lamination of a desired combination of power cores and signal cores. Vias remain unfilled until after lamination and are available to facilitate optical alignment of composite layers including signal cores, power cores and laminated combinations thereof.

Modular circuit package having vertically aligned power and signal cores

Rectangular preforms are vacuum picked and placed in each cavity of a first holder, and a measured amount of no-clean flux liquid is dispensed onto each preform, then a second holder is placed in an inverted position on top of the first holder and the holders are flipped so that the dry side of the preform is exposed and then a measured amount of no-clean solder is dispensed on the dry side of the preform. A robot arm with a rubber tipped vacuum probe picks up the preforms without damage or contamination and places them on a circuit board, grippers of the robot arm pick up and position a component on an induction coil to heat it up sufficient for reflow soldering, and then move the component onto the preform on the circuit board for reflow soldering. The circuit board can be used without cleaning with solvents or CFC's, thus reducing process steps and reducing environmental hazards.

Manufacturing solder-preform holders for a pick-and-place machine

Rectangular preforms are vacuum picked and placed in each cavity of a first holder, and a measured amount of no-clean flux liquid is dispensed onto each preform, then a second holder is placed in an inverted position (upside-down) on top of the first holder and the holders are flipped so that the dry side of the preform is exposed and then a measured amount of no-clean solder is dispensed on the dry side of the preform. The holders are unstacked and positioned on different sized posts extending upward from a pick-and-place machine. A robot arm with a rubber tipped vacuum probe picks up the preforms without damage or contamination and places them on a circuit board, grippers of the robot arm pick up and position a component on an induction coil to heat it up sufficient for reflow soldering, and then move the component onto the preform on the circuit board for reflow soldering.

Manufacturing circuit boards using a pick and place machine

Ten holders containing preforms are stacked on a rectangular bottom frame with different sized threaded posts of the bottom frame extending up through the hole and slot in opposite corners of each holder. An empty holder and then a dust cover with apertures at opposite corners are similarly stacked on the bottom frame to hold and protect the preforms. A top frame with apertures at opposite corners is positioned on the posts. The stack is compressed between the top frame and the bottom frame by screwing nuts onto the threaded posts to form a carrier in which the cavities are sized relative to the preforms to hold the preforms in position during transport to a pick-and-place machine without contaminating or damaging the delicate coating of dry flux. The holders are unstacked and positioned on different sized posts extending upward from a pick-and-place machine. A robot arm with a rubber tipped vacuum probe picks up the preforms without damage or contamination and places them on a circuit board, grippers of the robot arm pick up and position a component on an induction coil to heat it up sufficient for reflow soldering, and then move the component onto the preform on the circuit board for reflow soldering. The circuit board can be used without cleaning with solvents or CFC's, thus reducing process steps and reducing environmental hazards.

Solder preform pick-and-place machine and operation

A multi-layer printed circuit board or card including a plurality of circuitized power cores, the circuitized power cores include a layer of an electrically conductive material having a layer of electrically insulating material attached on both sides thereof. The circuitized power cores also include a plurality of plated through holes formed therethrough in substantially the same pattern on each circuitized power core. The circuitized power cores are parallel to each other such that corresponding plated through holes in the two circuitized power cores are co-linear. A plurality of substantially spherical balls are located between the circuitized power cores and are in contact with the corresponding plated through holes on facing cards. The balls have a diameter slightly larger than the opening of the plated through holes and are made of an electrically conductive material.

Method of making a printed circuit board or card

Disclosed is a method for manufacturing a stacked circuitized flex structure. The structure is a laminate for Z-axis communication within a parallel processor. This laminate portion provides XY plane and Z-axis interconnection for inter-processor, inter-memory, inter-processor/memory element, and processor to memory bussing interconnection, and communication. Z-axis circuitization is carried out by providing vias and through holes in individual circuitized flex strips. These vias and through holes are circuited and plated. This is followed by filling the vias and through holes with solder and forming solder bumps at the tops and bottoms of the vias and through holes. A sticker sheet with clearance holes for the solder bumps is provided, and a plurality of the circuitized flex strips are laid up for lamination to form a stack of circuitized flexible strips. Lamination is carried out at elevated pressure and temperature to crush the solder bumps, bond, and homogenize solder bump material and fuse the sticker sheets. Next, the stack is cooled to solidify the homogenized solder bump material.

Method of fabricating a parallel processor package

Clear thermoplastic is vacuum molded to produce rectangular, frustro-pyramidal shaped cavities in a horizontal matrix for holding rectangular solder preforms. No-clean flux liquid is dispensed onto a preform placed in each cavity, then another holder is placed upside-down on the first holder, the holders are flipped and then no-clean flux liquid is dispensed on the dry side of the preform. Holes in the cavity bottoms drain and circulate drying air to the preform bottoms. A hole in one corner and a different width slot in an opposite corner of each holder, allow multiple holders to be stacked on a bottom frame with different sized threaded posts. An empty holder and then a dust cover are stacked on the posts to hold and protect the preforms. A top frame is stacked on the posts and nuts are screwed onto the posts to form a carrier. The cavities are sized relative to the preforms to hold the preforms in position during carrier transport. The holders are unstacked and each positioned at a station with different sized posts on a rotating table of a pick-and-place machine. A robot arm with rubber tipped vacuum probe picks up the preforms and places them on a circuit board. Grippers on the arm are used to move a heated component on top of the preform for reflow soldering. The circuit board can be used without cleaning with solvents or CFC's.

Solder preform carrier and use

Method and apparatus are disclosed for mounting a flexible film semiconductor chip carrier on a second level electronic package. The resulting electronic packaging structure includes electrically conductive spacers, such as solder balls or solder coated copper balls, which electrically interconnect outer lead bonding pads on the flexible film semiconductor chip carrier and corresponding bonding pads on the second level electronic package, and which physically support the flexible film of the semiconductor chip carrier substantially in a plane above the surface of the second level electronic package. This electronic packaging structure is made using a special assembly fixture comprising a base plate, a pressure insert with a resilient member, and a top plate. The flexible film semiconductor chip carrier with the spacers attached thereto is placed over the resilient member of the pressure insert which is clamped together with the second level electronic package between the top and base plates. Then, this assembly is heated to reflow the solder of the spacers, and the assembly fixture is disassembled,; leaving the flexible film semiconductor chip carrier mounted on the second level electronic package with the flexible film of the carrier having a planar geometry as desired.

Method and apparatus for mounting a flexible film semiconductor chip

An electrical assembly which includes a first circuit member (e.g., TCM) with at least one conductive pin projecting therefrom for being frictionally and electrically engaged by a flexible portion of circuit means of a second circuit member (e.g., PCB). An opening is provided within the PCB relative to the flexible portions such that these portions project at least partly across the opening and frictionally engage respective conductive portions of the pin when inserted within the opening. Each of these flexible portions in turn is part of a circuit layer which may be coupled to respective conductive planes or the like within the PCB, while the respective conductive portions of the pin may in turn be electrically coupled to various conductive layers within/upon the TCM.

Electrical assembly with flexible circuit

Method and apparatus are disclosed for mounting a flexible film semiconductor chip carrier on a second level electronic package. The resulting electronic packaging structure includes electrically conductive spacers, such as solder balls or solder coated copper balls, which electrically interconnect outer lead bonding pads on the flexible film semiconductor chip carrier and corresponding bonding pads on the second level electronic package, and which physically support the flexible film of the semiconductor chip carrier substantially in a plane above the surface of the second level electronic package. This electronic packaging structure is made using a special assembly fixture comprising a base plate, a pressure insert with a resilient member, and a top plate. The flexible film semiconductor chip carrier with the spacers attached thereto is placed over the resilient member of the pressure insert which is clamped together with the second level electronic package between the top and base plates. Then, this assembly is heated to reflow the solder of the spacers, and the assembly fixture is disassembled, leaving the flexible film semiconductor chip carrier mounted on the second level electronic package with the flexible film of the carrier having a planar geometry as desired. The spacers may be attached to the flexible film semiconductor chip carrier using a special template having a pattern of openings corresponding to the pattern of outer lead bonding pads on the flexible film semiconductor chip carrier.

Apparatus for applying solder paste to printed circuit boards ('PCB's') in a continuous operation. A drum containing solder paste is positioned over a work station and has an outlet slot through which the solder paste can be discharged onto the surface of a PCB as it advances through the work station. A stencil formed with a desired pattern for application of the solder paste to the PCB is rotatably mounted on the outer surface of the drum and overlies the outlet slot. Gravity, machine vibration, and, if desired, air pressure are effective to discharge the solder paste onto the PCB with the aid of a resilient squeegee pad adjacent the outlet slot. A drive mechanism directly couples the translational movement of the PCB through the work station with the rotational movement of the stencil at the work station.

Continuous solder paste dispenser

Stripping and cutting apparatus in which a pair of disc cutters are affixed on a common rotatable shaft that is pivotably mounted to a rotating head. An object having an inner core member and an outer concentric member, which in the preferred embodiment is insulated conductive tubing, is advanced through a central opening in the head. The speed of the head is controlled so that at one speed the shaft is centripetally pivoted to an inner radial position that causes the closest of the cutters to block the leading end of the object, and so that at another faster speed the shaft is centrifugally pivoted to an outer radial position which removes the particular cutter from the blocking relationship with the leading end of the object thereby allowing the object to be advanced past the remote cutter for a predetermined distance, and so that at another speed, which is less than the last mentioned speed, the shaft is centripetally pivoted inward to provide concurrent cutting of the object by the two disc cutters. One of the cutters cuts a piece from the object and another cuts a portion of the outer member of the object, which portion is stripped from the cut piece by and between the cutters. The aforementioned closest cutter acts as reference plane for cutting the object in respective uniform lengths for the pieces and/or portions.

Centripetal cutter and stripper apparatus

Multiple pins are affixed in the holes of a ceramic substrate by simultaneously impacting the pins with a piston assembly which temporarily places the pins in a viscoelastic fluid state. Upon return of the pins and the resultant fluid flow to its undisturbed solid state, each pin is left with an extension that is in interlocking engaged relationship with the ceramic particles of the substrate in the region surrounding the particular holes in which the pins have been located. The piston assembly is driven by a pneumatic high pressure system which is adjustable to the number of pins being simultaneously impacted. Release of the piston assembly is delayed until the air pressure becomes stabilized prior to impact. A vacuum pressure system returns the piston to its originating position after impact whereupon the piston assembly is ready for the next impact cycle.

Growing community of inventors

Endwell, NY, United States of America

Harold Kohn