摘要:
Wafers which are direct bonded to each other in accordance with prior art processes suffer from voids at their bonded interface. Annealing such composite structures at high temperature and high pressure (for silicon wafers preferably about 1,100.degree. C. and 15,000 psi) eliminates all voids which are not a result of the presence of a particle on one of the wafers at the time of mating.
摘要:
An apparatus for monitoring the curing of a fiber reinforced composite plastic which is cured at temperatures of the order of 350.degree. C. and an ultrasonic transducer assembly useful in the apparatus. The transducer assembly comprises a lithium niobate piezoelectric element having anisotropic coefficients of thermal expansion which is mounted on a metal base of the transducer assembly by means of a layer of structured copper. The structured copper is thermo-compression diffusion bonded to the lithium niobate element and to the metal base, and is compliant in a transverse direction to compensate for differential thermal expansions while affording good electrical and thermal conductivity and good acoustic coupling between the lithium niobate element and metal base.
摘要:
An apparatus for monitoring the curing of a fiber reinforced composite plastic which is cured at temperatures of the order of 350.degree. C. and an ultrasonic transducer assembly useful in the apparatus. The transducer assembly comprises a lithium niobate piezoelectric element having anisotropic coefficients of thermal expansion which is mounted on a metal base of the transducer assembly by means of a layer of structured copper. The structured copper is thermo-compression diffusion bonded to the lithium niobate element and to the metal base, and is compliant in a transverse direction to compensate for differential thermal expansions while affording good electrical and thermal conductivity and good acoustic coupling between the lithium niobate element and metal base.
摘要:
The bond between a structured copper heat sink member and a semiconductor wafer is inspected for voids and unbonds by a focused ultrasonic pulse transmission method. The small focused spot of ultrasound is transmitted along the structured copper strands and is attenuated in the lateral direction. The absence of a received pulse or a significantly reduced amplitude signal, as the assembled device is scanned with acoustic pulses, indicate flaws in the bond.
摘要:
Concentrated sunlight impinges on a large area photovoltaic device which is bonded to a highly pliable and thermally and electrically conductive structured copper strain relieving member; the lower face of the structured copper is sealed to a fluid cooled metal heat sink. Large power densities of sunlight are absorbed without appreciable temperature rise. The structured copper accommodates to the difference in expansion between the metal heat sink and the semiconductor wafer. Three embodiments utilize a single planar junction diode, an interdigitated diode, and series connected isolated junction diodes.
摘要:
Annealed copper foil (12) is coated with chromium film (16), followed by coating with an appropriate thickness of gold film (14) and is thermocompression bonded to an aluminum metallized substrate (18) on a silicon chip (30) to provide solderable, high current contacts to the chip. The foil is formed into appropriate electrical network-contact patterns (40) and is bonded to the silicon chip only where aluminum metallization exists on the chip. Leaf (wing) portions (46) of the foil extend beyond the boundaries of the silicon chip for subsequent retroflexing over the foil to provide electrical contact at predesignated locations (49). External contacts to the foil are made by penetrating through a ceramic lid positioned directly above the foil area. Thus, direct thermocompression bonding of a principally copper foil to aluminum semiconductor pads can replace current gold detent/bump connections by securing a copper conductor to a silicon chip through an intermetallic AuAl.sub.2 link and an aluminum stratum.
摘要:
A hermetically sealed package for a semiconductor device includes a lid through which the leads of the device extend vertically away from the chip through an aperture in the lid which is hermetically sealed by the external terminal or electrode. The package is compact, lightweight and free of magnetic materials.
摘要:
A composite structure comprising a symmetric bimetallic laminate bonded to a separate substrate is provided by eutectic bonding the bimetallic laminate to the substrate. A variety of beneficial structures can be provided.
摘要:
A silicon circuit board incorporates multiple levels of patterned conductors. First level upper and lower patterned conductors are situated on an insulation-coated, monocrystalline silicon substrate. Upper and lower, high resistivity, polycrystalline silicon layers, in turn, are situated on the first level upper and lower patterned conductors, respectively. Second level upper and lower patterned conductors are situated over the upper and lower polycrystalline silicon layers. Further levels of patterned conductors in the circuit board may be provided by iteratively forming on the board polycrystalline silicon layers and patterned conductors. Conducting feedthroughs in the circuit board provide electrical communication between various patterened conductors.
摘要:
Annealed copper foil (12) is coated with chromium film (16), followed by coating with an appropriate thickness of gold film (14) and is thermocompression bonded to an aluminum metallized substrate (18) on a silicon chip (30) to provide solderable, high current contacts to the chip. The foil is formed into appropriate electrical network-contact patterns (40) and is bonded to the silicon chip only where aluminum metallization exists on the chip. Leaf (wing) portions (46) of the foil extend beyond the boundaries of the silicon chip for subsequent retroflexing over the foil to provide electrical contact at predesignated locations (49). External contacts to the foil are made by penetrating through a ceramic lid positioned directly above the foil area. Thus, direct thermocompression bonding of a principally copper foil to aluminum semiconductor pads can replace current gold detent/bump connections by securing a copper conductor to a silicon chip through an intermetallic AuAl.sub.2 link and an aluminum stratum.