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:
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:
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:
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 device for preventing short circuits between solder joints in flip chip packaging. The dielectric interposer has a plurality of apertures or vias which correspond to the I/O pads on a chip and substrate. Preferably, the interposer comprises a polyester film, glass, alumina, polyimide, a heat curable polymer or an inorganic powder filler in an organic material. More preferably, the interposer contains an adhesive or has adhesive layers disposed on the linear surfaces of the interposer. Cone shaped solder elements are formed within the apertures of the interposer. The dielectric interposer is positioned between a chip and substrate in an electronic module and thermally reflowed to create an electrical and mechanical interconnection. The interposer prohibits contact between the solder joints by isolating each of the joints and corresponding bonding pads. The interposer also prevents over compression of the solder joints by acting as a stand off.
摘要:
A semiconductor device having C-4 solder connections is joined to a chip carrier having pads suitable for receiving the C-4 solder connections. Sacrificial solder is formed on the chip carrier pads and then planarized to result in a good, planar surface profile for joining to the semiconductor device.
摘要:
A pre-thermal reflown dielectric interposer having a plurality of vias traversing through the interposer which correspond to the I/O pads on a chip and substrate. Cone shaped solder elements reside within the vias, whereby these solder elements are cone shaped prior to thermal reflow to permit a reduced force for allowing some non-planarity for joining the chip to the substrate. The interposer may comprise a polyester film, glass, alumina, polyimide, a heat curable polymer or an inorganic powder filler in an organic material. The interposer may also have an adhesive or adhesive layers disposed on the linear surfaces thereof. The present pre-thermal reflown interposer prohibits contact between the solder joints by isolating each of the joints and corresponding bonding pads, as well as preventing over compression of the solder joints by acting as a stand off.
摘要:
A compressible interposer comprising an interposer sheet having a plurality of apertures filled with a dielectric material having a substantially uniform suspension of conductive particles therein forming a plurality of conductive sites. Preferably, the number of conductive sites on the interposer are greater in number than the number of contact pads on the electronic components such that precise alignment of the interposer between the electronic components is not required. The apertures of the interposer sheet confine the conductive particles within the dielectric material such that during compression of the interposer between the electronic components, z-axis conductive pathways are formed without shorting in the x and y directions. Preferably, the interposer sheet comprises polyimide. Preferably, the dielectric material comprises polyimide-siloxane. Preferably, the conductive particles have a diameter of about 2 to about 20 &mgr;m and comprise of a material selected from the group consisting of copper, gold, silver, nickel, palladium, platinum, and alloys thereof. The particles may also be coated with an additional conductive material such as solder having a lower melting temperature. Most preferably, the conductive particles comprise solder coated copper particles. The conductive particles are present in an amount of about 30 to about 90 wt. % of the total weight of the conductive particles and the dielectric material.
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:
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.