摘要:
A method and apparatus is provided for forming an electronic assembly whereby an insulating polymer matrix having a plurality of conductor holes is attached to a first substrate wherein the conductor holes align with a corresponding contact array on the first substrate. Subsequently, a flexible, electrically conductive adhesive is provided within the plurality of conductor holes and a solid conductive material, preferably having a high melting temperature, is attached to at least one end thereof. The insulating polymer matrix with the electrically conductive adhesive and the solid conductive material is then cured at a temperature sufficient to completely cure the matrix to completely surround the electrically conductive adhesive, as well as permanently attaching the matrix and conductive adhesive to the first substrate and permanently attaching the solid conductive material to the conductive adhesive. A second substrate may then be attached to the conductive matrix structure secured to the first substrate by providing a low melting temperature attachment means to the solid conductive material attached to the matrix and subsequently reflowing the assembly to form an electronic assembly adapted with the capability of reworkability.
摘要:
The invention is directed to improved conductive adhesives for solder-free interconnections in microelectronic assembly processes such as for chip carrier-to-substrate attachment. These adhesives are characterized by low tensile modulus, low resistivity, high adhesion strength, and durability of these properties during reliability stress conditions of thermal shock, thermal aging, and temperature/humidity (85° C./85%) exposure of the assembled devices. The adhesives contain a homogeneous solution of a siloxane containing epoxide, a curing agent, a curing catalyst and an organic polymeric or oligomeric additive. A conductive filler is added to the solution forming the filler. Preferred fillers are Ag coated with Pd and Ag coated with Au.
摘要:
A structure and method for converting a standard ceramic carrier into a temporary chip attach carrier, wherein the device comprises a substrate, a plurality of metal vias interspersed in the substrate, a carrier layer further comprising a cavity dam with a plurality of holes filled with conductive adhesive. The process of forming the temporary chip attach carrier comprises applying a secondary layer further comprising a plurality of holes on a substrate, applying conductive adhesive in the holes, curing the adhesive, placing a chip containing C4 solder bumps onto the secondary layer, applying a force onto the chip, testing and burning-in the secondary layer, removing the force from the chip, separating the chip from the secondary layer, and then re-using the secondary layer.
摘要:
This invention relates to a solder structure which provides enhanced fatigue life properties when used to bond substrates particularly at the second level such as BGA and CGA interconnections. The solder structure is preferably a sphere or column and has a metal layer wettable by solder and the structure is used to make solder connections in electronic components such as joining an electronic module such as a chip connected to a MLC which module is connected to a circuit board. The solder structure preferably has an overcoat of solder on the metal layer to provide a passivation coating to the metal layer to keep it clean from oxidation and corrosion and also provide a wettable surface for attachment of the solder structure to solder on the pads of the substrate being bonded.
摘要:
The present invention relates generally to a new method of repairing electrical lines, and more particularly to repairing electrical lines having an opening at the module level with devices in place. Various methods and processes are used to repair this open or defective portion in an electrical conductor line. It could be repaired by securing a jumper wire or nugget across the open or the repair could be made by a deposition process, which includes but is not limited to filling the opening with a solder type material or inserting a solder coated electrical wire and heating the solder and allowing the solder to melt and repair the open. One of the attributes of this invention is the ability to repair on a substrate or module on which active components such as chips, and passive components such as pins, capacitors, etc. have been attached. The invention also allows repair of fine line patterns which are normally not repairable by conventional techniques.
摘要:
A process and apparatus for removing flip chips with C4 joints mounted on a multi-chip module by applying a tensile force to one or more removal member bonded to the back of one or more flip chips during heating of the module to a temperature sufficient to cause the C4 joints to become molten. The tensile force can either be a compressed spring, or a bi-metallic member which is flat at room temperature and becomes curved when heated to such temperature, or a memory alloy whose original shape is curved and which is bent flat at room temperature but returns to its original curved shape when heated to such temperature. An adhesive is used to bond the removal member to the chip to be removed and is a low temperature, fast curing adhesive with high temperature tolerance after curing.
摘要:
This invention relates to a solder structure which provides enhanced fatigue life properties when used to bond substrates particularly at the second level such as BGA and CGA interconnections. The solder structure is preferably a sphere or column and has a metal layer wettable by solder and the structure is used to make solder connections in electronic components such as joining an electronic module such as a chip connected to a MLC which module is connected to a circuit board. The solder structure preferably has an overcoat of solder on the metal layer to provide a passivation coating to the metal layer to keep it clean from oxidation and corrosion and also provide a wettable surface for attachment of the solder structure to solder on the pads of the substrate being bonded.
摘要:
A method for removing at least one molten or solid structure from a surface including: placing the surface with the at least one molten or solid structure in a fixture; disposing said wiper assembly acted on by a bias proximate the at least one molten or solid structure; retaining the wiper assembly in a first position with a device having a first temperature point level equivalent to or higher than a second melting point level of the at least one molten or solid structure; and raising the temperature of the fixture to the first temperature point level; wherein the at least one molten or solid structure is wiped from the surface when the device reaches the first temperature point level. An apparatus for removing at least one molten or solid structure from a substrate for rework, the apparatus comprising: a fixture for sustaining and biasing the substrate against a wiper assembly; the wiper assembly configured and positioned to slidably engage at least a portion of the substrate; a bias for translating the wiper assembly along a surface of the substrate having the at least one molten or solid structure to be removed; and a guide block assembly capable of guiding and locking the wiper assembly.
摘要:
A process and apparatus for removing flip chips with C4 joints mounted on a multi-chip module by applying a tensile force to one or more removal member bonded to the back of one or more flip chips during heating of the module to a temperature sufficient to cause the C4 joints to become molten. The tensile force can either be a compressed spring, or a bimetallic member which is flat at room temperature and becomes curved when heated to such temperature, or a memory alloy whose original shape is curved and which is bent flat at room temperature but returns to its original curved shape when heated to such temperature. An adhesive is used to bond the removal member to the chip to be removed and is a low temperature, fast curing adhesive with high temperature tolerance after curing.
摘要:
The present invention relates generally to a new method of repairing electrical lines, and more praticularly to repairing electrical lines having an open at the module level with devices in place. Various methods and processes are used to repair this open or defective portion in an electrical conductor line. It could be repaired by securing a jumper wire or nugget across the open or the repair could be made by a deposition process, which includes but is not limited to filling the open with a solder type material or inserting a solder coated electrical wire and heating the solder and allowing the solder to melt and repair the open. One of the attributes of this invention is the ability to repair on a substrate or module on which active components such as chips, and passive components such as pins, capacitors, etc. have been attached. The invention also allows repair of fine line patterns which are normally not repairable by conventional techniques.