Abstract: Preferred embodiments for methods of removing an integrated circuit (“IC”) from a substrate, where the IC is attached to the substrate by multiple solder connections are disclosed. One preferred embodiment of the inventive methods provides the steps of heating the IC and substrate to the reflow temperature for the solder connections and pulling the IC from the substrate by means of a vacuum force. Another preferred embodiment of the inventive method provides the step of shearing the IC from the substrate after the substrate and IC are heated, but before solder reflow temperature has been reached, and where the shearing force may be programmed through a computer controlled servomotor. Preferred embodiments of certain apparatus applying the inventive methods for removing an integrated circuit from a substrate are also disclosed.

Abstract: A method for joining a multiplicity of multi-alloy solder columns to an electronic substrate and the structure formed by such method are disclosed. In the method, a mold plate equipped with a multiplicity of cavities is first filled by an injection molded solder technique with a high temperature solder forming a multiplicity of solder columns. The mold plate is then sandwiched between an extraction plate and a transfer plate by utilizing a multiplicity of displacement means equipped in the extraction plate to displace the multiplicity of solder columns from the mold plate into a multiplicity of apertures equipped in the transfer plate. The multiplicity of cavities in the transfer plate each has a straight opening and a flared opening. The flared opening is then filled with a low temperature solder paste to encapsulate one end of the high temperature solder column.

Abstract: A method for joining a multiplicity of multi-alloy solder columns to an electronic substrate and the structure formed by such method are disclosed. In the method, a mold plate equipped with a multiplicity of cavities is first filled by an injection molded solder technique with a high temperature solder forming a multiplicity of solder columns. The mold plate is then sandwiched between an extraction plate and a transfer plate by utilizing a multiplicity of displacement means equipped in the extraction plate to displace the multiplicity of solder columns from the mold plate into a multiplicity of apertures equipped in the transfer plate. The multiplicity of cavities in the transfer plate each has a straight opening and a flared opening. The flared opening is then filled with a low temperature solder paste to encapsulate one end of the high temperature solder column.

Abstract: An apparatus for removing a casting comprising an electronic package substrate and an array of cast solder columns having a column pitch of less than 2 mm extending therefrom from the corresponding openings of a mold. The apparatus includes a removable mold containing a plurality of openings for casting a corresponding array of solder columns and bonding the columns to the underside of an electronic package substrate. A stripper plate for receiving the mold contains openings through a thickness thereof corresponding to at least some of the openings in the mold. An ejector assembly including ejector pins having a length at least as long as the sum of the thickness of the stripper plate at the stripper plate openings and the thickness of the mold at the column casting openings, and corresponding to openings in the mold and the stripper plate.

Abstract: A method and apparatus for loading solder balls into a mold. Solder balls are loaded into a reservoir having multiple exit ports. A removable mold is fitted into the apparatus and the reservoir is passed across the top of the mold while solder balls are fed into cavities in the mold. After the reservoir has advanced across the mold and the mold cavities are filled with solder balls, the reservoir is reset as a roller is simultaneously guided across the mold to seat the solder balls firmly within the mold. Alternatively, the roller may be applied to the solder balls while the reservoir advances across the mold, or both as the the reservoir is advanced and when it is returned to its original position.

Abstract: Disclosed is a solder injection mold apparatus and method for providing solder balls to a printed circuit board substrate using the solder injection mold apparatus in the plastic ball grid array (PBGA). The solder mold through holes are chamfered at entry and at exit ends to assist in receipt of molten solder and the formation and transfer of solder balls to lands on the substrate. A blind recess is provided in the second major surface of the mold, i.e. the side facing the substrate, in order to accommodate electronic components mounted thereon. Solder balls are delivered and metallurgically affixed to the lands in a process that requires only one reflow, leaving the through holes clean of solder and the mold ready for reuse. The material of which the substrate, mold and base plate are comprised is selected to be non-wettable by solder and mutually compatible with respect to CTE when exposed to temperatures of molten solder.

Abstract: Disclosed is a solder injection mold apparatus and method for providing solder balls to a printed circuit board substrate using the solder injection mold apparatus in the plastic ball grid array (PBGA). The solder mold through holes are chamfered at entry and at exit ends to assist in receipt of molten solder and the formation and transfer of solder balls to lands on the substrate. A blind recess is provided in the second major surface of the mold, i.e. the side facing the substrate, in order to accommodate electronic components mounted thereon. Solder balls are delivered and metallurgically affixed to the lands in a process that requires only one reflow, leaving the through holes clean of solder and the mold ready for reuse. The material of which the substrate, mold and base plate are comprised is selected to be non-wettable by solder and mutually compatible with respect to CTE when exposed to temperatures of molten solder.

Abstract: The present invention relates generally to a new scheme of providing a seal for semi-conductor substrates and chip carriers. More particularly, the invention encompasses a structure and a method that uses a multi-layer metallic seal to provide protection to chips on a chip carrier. This multi-layer metal seal provides both enhanced hermeticity lifetime and environmental protection.For the preferred embodiment the multi-layer metallic seal is a two layer, solder structure which is used to create a low cost, high reliability, hermetic seal for the module. This solder structure has a thick high melting point temperature region that is attached to a cap, and a thin interconnecting region of lower melting point temperature region for sealing the substrate to the cap.

Abstract: An apparatus and method are provided for continuously injecting molten solder into a plurality of molds for transfer of the formed solder mounds to electronic devices such as multilayer ceramic packages. A conventional injection molding apparatus is employed with a specially designed apparatus for forming the molds and preferably with a specially designed mold to provide a continuous molding process. The apparatus is preferably of a U-shaped configuration whereby molds are advanced under the molten solder reservoir and injection head by a preceding mold in the apparatus. The urging action of the preceding mold on the succeeding mold and, preferably in conjunction with the preferred mold design, enables a continuous method and apparatus for injecting molten solder into a plurality of molds.

Abstract: A fixture for securing a circuit chip substrate having on one side solder connections during wet processing using a pulse jet delivery cleaning system for removing solder flux residue on the solder connections. The fixture comprises a frame of sufficient size to at least partially surround and contact the substrate on a first side and a lid cooperating with the frame to at least partially cover the substrate on a second side containing the solder connections. A resilient polymeric separator is disposed on the lid and faces the substrate for contacting the substrate second side containing the solder connections. There are also openings in the frame for permitting circulation of a cleaner to contact the second side of the substrate.

Abstract: The present invention relates generally to a new scheme of providing a seal for semi-conductor substrates and chip carriers. More particularly, the invention encompasses a structure and a method that uses a multi-layer metallic seal to provide protection to chips on a chip carrier. This multi-layer metal seal provides both enhanced hermeticity lifetime and environmental protection. For the preferred embodiment the multi-layer metallic seal is a two layer, solder structure which is used to create a low cost, high reliability, hermetic seal for the module. This solder structure has a thick high melting point temperature region that is attached to a cap, and a thin interconnecting region of lower melting point temperature region for sealing the substrate to the cap.

Abstract: The present invention relates generally to a new apparatus and a method for alignment verification. More particularly, the invention encompasses an apparatus that allows the imaging on a structure from opposite sides while the imaging masks are on the opposite sides of the structure, and the masks and the structure are all aligned with each other. This apparatus also discloses means that can verify that the two imaging masks that are on the opposite sides of each other are aligned with each other during imaging processing.

Abstract: A photo resist drier for curing photo resist coatings on a metal foil is described. The dryer has an enclosure made of copper sheet and surrounded by strip heaters to heat the enclosure. The enclosure, heated by the heaters conducts heat and accordingly results in a more uniform internal temperature in the enclosure. The heaters are individually controllable. The vapors are captured by an exhaust system and removed from the dryer.