摘要:
A bumped semiconductor device (10) exhibiting enhanced pattern recognition when illuminated in a machine vision system. The semiconductor device has a substantially coplanar array of solder bumps (16) and a coating of underfill material (17) on one face. A fluxing composition (18) containing an image enhancing agent is selectively deposited over at least two of the solder bumps in the array to modify the optical characteristics of the solder bumps to cause the solder bumps to appear bright against the background of the underfill material when the semiconductor device is illuminated (19) by selected wavelengths of light.
摘要:
The invention provides a method for attaching a flip chip to an electrical substrate such as a printed wiring board. A bumped flip chip is provided, the flip chip including an active surface and a plurality of connective bumps extending from the active surface, each connective bump including a side region. A thin layer of an underfill material is applied to the active surface of the flip chip and to a portion of the side regions of the connective bumps. The flip chip is positioned on the electrical substrate, the electrical substrate including a thick layer of a solder mask disposed on the electrical substrate. The flip chip is heated to electrically connect the flip chip to the electrical substrate, wherein the underfill material and the solder mask combine to form a stress-relief layer when the flip chip is electrically connected to the electrical substrate.
摘要:
The invention provides a method of attaching an area-array device such as a bumped flip chip to an electrical substrate. An underfill material is applied to a portion of the electrical substrate, and the underfill material is heated to an underfill-material staging temperature. A bumped area-array device is provided, the bumped area-array device including an interconnection surface and a plurality of connective bumps extending from the interconnection surface. The interconnection surface of the bumped area-array device is positioned adjacent the applied underfill material. The bumped area-array device is heated to electrically connect the connective bumps to the electrical substrate. The invention also provides a flip-chip assembly and a printed wiring board panel with pre-applied underfill material.
摘要:
A method for providing an underfill material on an integrated circuit chip at the wafer level. The wafer (10) typically contains one or more integrated circuit chips (12), and each integrated circuit chip typically has a plurality of solder bumps (34) on its active surface. The wafer is first diced (22) on the active surface side to form channels (38) that will ultimately define the edges (39) of each individual integrated circuit chip, the dicing being of such a depth that it only cuts part-way through the wafer. The front side (36) of the wafer is then coated (24) with an underfill material (40). Generally, a portion (45) of each solder bump remains uncoated, but in certain cases the bumps can be completely covered. The back side of the wafer is then lapped, ground, polished or otherwise treated (26) so as to remove material down to the level of the previously diced channels. This reduction in the thickness of the wafer causes the original diced channels to now extend completely from the front side to the back side of the wafer. The wafer is then singulated (28) by cutting the underfill material (92) that was deposited in the channels during the coating step, so that the integrated circuit chip (12) is released from the wafer, and the underfill material that was coated on the active side remains affixed to the active surface of each individual integrated circuit chip.
摘要:
A cold cathode device (20) includes a grid (24), a cold cathode (21) positioned under the grid, and a shield electrode (26) positioned above and parallel to the grid. A vacuum gauge includes a shell (32), a collector (39), an anode (38), and the cold cathode device of the present invention. The cold cathode device and the collector are positioned symmetrically relative to the anode. The collector, the grid and the cold cathode device are received in the shell. The shield electrode can shield an electric field of the grid for preventing from disturbing a symmetrical saddle field in the vacuum gauge. Electrons produced by the cold cathode device can obtain a long electron track because the electron vibration in the saddle field is symmetrical. Thus, the vacuum gauge has an improved sensitivity, and can be widely used to measure pressure in ultra-high and extremely high vacuum conditions.
摘要:
Two and three dimensional polynucleic acid structures, such as periodic lattices, may be constructed from an ordered array of antiparallel double crossover molecules assembled from single stranded oligonucleotides or polynucleotides. These antiparallel double crossover molecules have the structural rigidity necessary to serve as building block components for two and three dimensional structures having the high translational symmetry associated with crystals.
摘要:
An ionization vacuum gauge includes a cathode, an anode and an ion collector. The ion collector component is located at one side of the anode component and spaced from the anode component. The cathode component is located at another side of the anode component and includes an electron emitter, which extends toward the anode component from the cathode component. The electron emitter includes at least one carbon nanotube wire.
摘要:
Disclosed herein are materials and methods for sensitizing multidrug resistant cancer cells that express ABCG2 and related proteins members of a family of ATP-binding transporter superfamily that mediate drug efflux found in some types of multidrug resistant caner cells. A series of compounds, including (N-(4-chlorophenyl)-2-[(6-{[4,6-di(4-morpholinyl)-1,3,5-tri-azin-2-yl]amino}-1,3-benzothiazol-2-yl)sulfanyl]acetamide), specifically inhibits ABCG2 and can be used to boost the bio-avail-ability of one or more effective cancer killing drugs, making it possible to use certain widely used chemotherapeutic reagent to treat multidrug resistance cancers. Using these compounds in combination with chemotherapeutic drugs that are substrates for ABCG2 and related proteins may also find utility in treating cancer cells that are not currently identified as multi-drug resistant Additionally, these compounds appear to accelerate the intercellular degradation of ABCG2 and related proteins. They are not toxic to animals at levels at which they effect the activity of ABCG2 expressed in multi-drug resistant cancer lines.