摘要:
A process for underfilling a chip-under-chip module. The module comprises a first larger chip, a second smaller chip attached to the underside of the first chip, a substrate having a top surface to which the first chip is mounted, a cavity into which the second chip fits when the first chip is mounted on the top surface, and an access channel connecting the cavity to the top surface. Underfill is disposed under the first chip between the first chip and the substrate, between the first and second chips, within the cavity, and within the access channel. The process for underfilling such a module comprises the steps of forming the substrate having the cavity and access channel in the substrate, connecting the first chip to the substrate, and dispensing underfill through the access channel.
摘要:
A chip-under-chip module and a substrate for making the module. The module comprises a first larger chip, a second smaller chip attached to the underside of the first chip, a substrate having a top surface to which the first chip is mounted, a cavity into which the second chip fits when the first chip is mounted on the top surface, and an access channel connecting the cavity to the top surface. Underfill is disposed under the first chip between the first chip and the substrate, between the first and second chips, within the cavity, and within the access channel. A process for manufacture of such a module comprises the steps of forming the substrate having the cavity and access channel in the substrate, connecting the first chip to the substrate, and dispensing underfill through the access channel.
摘要:
A semiconductor module structure and a method of forming the semiconductor module structure are disclosed. The structure incorporates a die mounted on a substrate and covered by a lid. A thermal compound is disposed within a thermal gap between the die and the lid. A barrier around the periphery of the die extends between the lid and the substrate, contains the thermal compound, and flexes in response to expansion and contraction of both the substrate and the lid during cycling of the semiconductor module. More particularly, either the barrier is formed of a flexible material or has a flexible connection to the substrate and/or to the lid. The barrier effectively contains the thermal compound between the die and the lid and, thereby, provides acceptable and controlled coverage of the thermal compound over the die for heat removal.
摘要:
A system to improve an in-line memory module may include an edging carried by the in-line memory module to stiffen, support, protect, and/or aid in handling the in-line memory module. The system may also include guide ribs carried by the edging to facilitate positioning of the in-line memory module during installation. In one embodiment, the system includes a heat spreader to aid in cooling a plurality of heat sources carried by the in-line memory module. The system may further include a compliant member to regulate the heat spreader's positioning relative to the plurality of heat sources.
摘要:
A method for assembling, and the resultant electronic module, includes attaching a chip to a substrate using a first solder interconnection array, and attaching a board to the substrate using a second solder interconnection array, which may be a single-melt or a dual-melt solder array. The second solder interconnection array resides entirely within a space defined between the board and substrate. A creep resistant structure is provided within this space for maintaining the defined space and optimizing integrity of the second solder interconnection array. The creep resistant structure may include an underfill material, balls, brackets, frames, collars or combinations thereof. Wherein the creep resistant structure is an underfill material, it is crucial that the substrate be attached to the board before either entirely encapsulating the second interconnection array with underfill material, or partially encapsulating the second solder interconnection array at discrete locations with underfill material.
摘要:
Methods, apparatus and assemblies for enhancing heat transfer in electronic components using a flexible thermal pillow. The flexible thermal pillow has a thermally conductive material sealed between top and bottom conductive layers, with the bottom layer having a flexible reservoir residing on opposing sides of a central portion of the pillow that has a gap. The pillow may have roughened internal surfaces to increase an internal surface area within the pillow for enhanced heat dissipation. In an electronic assembly, the central portion of the pillow resides between a heat sink and heat-generating component for the thermal coupling there-between. During thermal cycling, the flexible reservoir of the pillow expands to retain thermally conductive material extruded from the gap, and then contracts to force such extruded material back into the gap. An external pressure source may contact the pillow for further forcing the extruded thermally conductive material back into the gap.
摘要:
The present invention relates generally to a new structure and a method for reducing the cost of producing known good die (KGD). More particularly, the invention encompasses a structure and a method that uses a substrate having solder wettable pads, a chip with attached solder balls, and a thin non-conductive interposer that is assembled between the chip and the substrate. The interposer reduces the cross section of the solder connections from the chip to the substrate where the solder passes through (the holes in) the interposer. This reduced cross-sectional area of the solder connection creates a weak point which allows the chip to be easily sheared off of the substrate after a burn-in and test process. The preferred chips for this invention are flip chips.
摘要:
Integrated circuit chip packaging modules and lid structures having improved heat dissipation performance are characterized by a customized lid understructure which enables a reduction in the amount of compliant thermally conductive material in the primary heat dissipation path. The lid structures and modules are made by processes wherein the lid understructure is customized for the chip(s) to be housed. The customization is achieved by the use of shims and a deformable lid understructure.
摘要:
The invention concerns an in vitro process for altering the insect host range (spectrum) or increasing the toxicity of lepidopteran active B.t. crystal protein toxins. The process comprises recombining in vitro the variable region(s) (non-homologous) of two or more genes encoding lepidopteran active B.t. crystal protein toxins. Specifically exemplified is the recombining of the variable regions of two genes obtained from well-known strains of Bacillus thuringiensis var. kurstaki. The resulting products are chimeric toxins which are shown to have an expanded and/or amplified lepidopteran insect host range as compared to the parent toxins.
摘要:
The invention concerns novel hybrid pesticidal toxins. These toxins are expressed as the fusion protein of a chimeric gene. Specifically exemplified is a novel B.t. hybrid toxin. These novel toxins have increased toxicity against target pests. The invention also concerns a process for preparing a hybrid virus having an altered insect host range.