摘要:
A circuit for controlling power consumption of a load, by controlling the flow of current thereto, utilizes at least one parallel combination of non-linear resistance elements, such as a varistor and the like, and a gateable semiconductor switching device, such as a triac and the like, to substantially reduce or prevent current flow when the semiconductor switching device is gated to an "off" condition and to enable normal current flow to a load when the semiconductor switching device is gated to an "on" condition. Embodiments of the power circuits for control of magnetron power, in a microwave oven, are illustrated.
摘要:
A power supply for controlling the duty-cycle of a microwave oven magnetron and the like power-energizing load, includes a parallel combination of a non-linear resistance element, such as a varistor and the like, and a gateable semiconductor switching device, such as a triac and the like, in series with a power supply voltage-doubler diode, connected in parallel across the magnetron. The flow of current through the magnetron is substantially reduced or prevented when the semiconductor switching device is gated to an "off" condition and is substantially enabled to a normal current flow value when the semiconductor switching device is gated to an "on" condition, typically by high frequency squarewaves provided at the gate electrode.
摘要:
A body is hermetically sealed by electroplating a hermetic layer over the exterior surface of the body. A hermetic high density interconnect structure is provided by forming a continuous metal layer over the outermost dielectric layer of the multilayer interconnect structure and by disposing that continuous metal layer in a hermetically sealing relation to the substrate of the high density interconnect structure. A variety of techniques may be used for providing electrical feedthroughs between the interior and exterior of the hermetic enclosure as may a pseudo-hermetic enclosure in those situations where true hermeticity is not required.
摘要:
A mixture for affixing dice to a substrate includes a thermoplastic polyimide, a solvent for the polyimide, and a solvent which does not dissolve the polyimide but adds thixotropicity to the mixture. The mixture is applied to the substrate, the dice are placed thereon, and the solvents are evaporated to bond the dice to the substrate. The bond is radiation hard and exhibits high shear pull strength. A poor solvent for the polyimide, sprayed over the dice and exposed portions of die attach material, causes some polyimide to precipitate out of solution in the exposed portions of die attach material to form a grid that extends between the dice and prevents the dice from "swimming together" during high temperature processing. In a solvent die-attachment method, the substrate is first coated with a mixture of die attach material, and the mixture is dried. Spraying a solvent over the die attach material causes the material to soften so that the dice applied thereto may adhere. The die attach material is then dried to form the bond.
摘要:
A high density interconnect structure incorporating a plurality of laminated dieletric layers is fabricated using thermoplastic adhesive layers of progressively lower glass transition temperature in order to maintain the stability of the already fabricated structure during the addition of the later laminations. This structure also facilitates the removal of only a portion of the high density interconnect structure where a fault in the system can be corrected in one of the upper layers of the high density interconnect structure.
摘要:
A dual layer resist configuration is employed for photopatterning high resolution conductive patterns on underlying polymeric or ceramic substrates, particularly substrates exhibiting surface roughness and non-planar design features such as channels, bosses and ridges. More particularly, a thin underlayer of ablatable photoabsorptive polymer is disposed on a metal coated substrate, after which a thicker layer of substantially transparent material is disposed over the polymer. A beam of laser energy, such as that produced by an ultraviolet excimer layer, is directed through the upper layer and is absorbed by the lower layer which is ablated and simultaneously removes the thick layer above it. This results in the ability to etch high resolution features on polymeric and other substrates, particularly copper coated polyetherimide circuit boards. The resist system is also applicable to VLSI wafers even though such wafers usually do not exhibit surface roughness on the scale generally considered herein. It is also equally applicable in various high density interconnect systems used for the direct connection of chip devices. A mask for patterning and a method for making it are also seen to be desirable because of the high laser energy densities generally desired for thorough ablation. An alternate method is also disclosed which employs two laser exposure steps with the first step being a masked operation on only an ablatable layer and with the second step being an unmasked operation on a dual layer material.
摘要:
A multichip integrated circuit package comprises a substrate to which is affixed one or more integrated circuit chips having interconnection pads. A polymer film overlying and bridging integrated circuit chips present is provided with a plurality of via openings to accommodate a layer of interconnection metallization which serves to connect various chips and chip pads within the interconnection pads disposed on the chips. A significant advantage of the packaging method and configuration of the present invention is the ability for the polymer film to be removed. This significantly improves testability and effectively provides wafer scale integration circuit packages which are free of problems associated with yield and testability.
摘要:
A method for producing holes in a polymer film includes the steps of irradiating a spot on the film with a burst of focused laser energy at a level sufficient to damage the film without puncturing it and then subsequently plasma etching the irradiated film so as to remove the damaged portions. This method is particularly applicable to the formation of multichip integrated circuit packages in which a plurality of microcircuit chips are affixed to an underlying substrate which is coated with a polymer film covering the chips and the substrates. The holes are provided for the purpose of interconnecting the chips or making intrachip connections by means of a subsequently applied metallization layer.
摘要:
A self-standing cooking apparatus is disclosed which consists of a pressurizable vessel having a door which can be latched and sealed, an integral steam-pressure source and integral upper and lower heating rod elements which serve as broil elements and bake elements, respectively, and a water-filled tray which can be disposed above the upper heating rod. An electrical control circuit enables selective energization of the bake and broil heat elements by continuous or controlled duration pulses of current which control the proportion of infrared energy that will be produced by the heating rods. The oven can be operated under pressure with the heating rods applying infrared radiation to the foodstuff being cooked in order to obtain browning or crisping of the foodstuff which is cooked at elevated pressure. The oven can also be operated in a conventional bake mode, a conventional broil mode, a steam cooking mode, a sealed cooking and warming mode and a toasting mode. Reinforcing fins lying in parallel planes are secured to and encircle the exterior of the container to provide necessary additional strength for the pressurizable vessel walls to withstand a maximum design pressure.
摘要:
A low-cost conductor, e.g. a printed circuit, is prepared by applying a mixture of a metallic powder and polymer on a substrate and curing the polymer, followed by an augmentation replacement reaction being effected to replace some of the metallic powder with a more noble metal in such a way that the total volume of deposited metal on the surface exceeds that of the original metal powder at that surface. This procedure produces contiguous layer of conducting metal on the substrate. The conductors thus formed can easily be soldered without leaching using a conventional tin-lead solders.