Peter Collier - Academia.edu (original) (raw)
Papers by Peter Collier
Proceedings of the 1997 1st Electronic Packaging Technology Conference (Cat. No.97TH8307)
Processes with potential for low cost flip-chip on board assembly were investigated in order to p... more Processes with potential for low cost flip-chip on board assembly were investigated in order to populate conventional printed circuit cards directly or to replace wire bonding in ball grid array packages. Overall aspects of wafer bumping, device placement, underfill encapsulation and assembly integrity were addressed. Two types of wafer bumping process were evaluated, involving fine pitch stencil printing of solder
International Journal of Nanoscience, 2005
We have studied the metal-molecule interface linkage effects of metal-molecule-metal systems by f... more We have studied the metal-molecule interface linkage effects of metal-molecule-metal systems by first principles method, which is based on density functional theory (DFT) and nonequilibrium Green's functions (NEGF) to calculate the electron transport of open metal-molecule-metal systems. Metal electrodes are described through 3-D atomic model instead of a non-atomic (like Jellium model) description. Several open systems are constructed, optimized and simulated. Sulphur atom (S) and cyano-group (CN) are employed to connect Au electrodes and molecule borazine/benzene. The density of states (DOS) and the transmission functions (TF) of constructed systems are investigated. Results show that DOS of the systems are affected little but transmission properties a lot by terminal groups CN and S. The peaks in the TF mismatch with those in DOS and the mismatch resulting from terminal group CN is larger than it from terminal atom S. Calculated transmission functions show that the systems wi...
Proceedings of the 5th Electronics Packaging Technology Conference (EPTC 2003)
Processes for producing tantalum pentoxide thin film capacitors and tantalum nitride thin film re... more Processes for producing tantalum pentoxide thin film capacitors and tantalum nitride thin film resistors in a combined process flow with multi-level interconnects are demonstrated, as may be applied to wafer level packages or thin film modules. Considerations of materials property and component parameter relations are presented in order to fabricate stable, high tolerance devices. Process capability indices are discussed, based
2006 IEEE Conference on Emerging Technologies - Nanoelectronics
... molecules, Nature, Vol. 403, pp.635-638, 2000. [11] W. Tian, S. Datta, AHARONOV-BOHM-TYPE E... more ... molecules, Nature, Vol. 403, pp.635-638, 2000. [11] W. Tian, S. Datta, AHARONOV-BOHM-TYPE EFFECT IN GRAPHENE TUBULES - A LANDAUER APPROACH, Phys. Rev. B, Vol. 49, pp.5097-5100, 1994. [12] H. Mehrez ...
2006 Sixth IEEE Conference on Nanotechnology
We investigate the electron conductance of thiophene oligomers based molecular wires using the fi... more We investigate the electron conductance of thiophene oligomers based molecular wires using the first principles method, which is based on the density functional theory and nonequilibrium Green's function. The molecular wires are built by bridging various thiophene oligomers (dimers, tetramers and hexamers with different inter-ring torsional angles) between two gold electrodes via terminal groups S and CN. The projected energy levels, energy gaps, transmission functions and current-voltage characteristics of the molecular wires are calculated and analyzed. Results show that the molecular wires with the planar structures of thiophene oligomers have larger electron transmission functions, hence better electronic conductance than those with twist structures. The conductance of molecular wires decreases when the chain length of the thiophene oligomer increases. The terminal groups between the oligomer and the electrode has nontrivial effects on the conductance of the wires. The results could provide a qualitative guidance for design molecular electronic wires.
Soldering & Surface Mount Technology, 2002
A challenge in selecting and applying lead‐free solders lies in separating the influences of mate... more A challenge in selecting and applying lead‐free solders lies in separating the influences of materials' properties, fluxes and processes to obtain robust assembly conditions that are compatible with PCB finishes and all component terminations. This paper discusses simple steps towards establishing a lead‐free assembly process. With reference to results of solder paste spread and wetting tests and component solderability tests, some of the current limitations in applying standard test methods to lead‐free evaluations are highlighted.
IEEE Transactions on Nanotechnology, 2005
The effects of terminal groups on the electron transport between metal electrodes and molecule ar... more The effects of terminal groups on the electron transport between metal electrodes and molecule are investigated through metal-molecule-metal systems using the first principles method, which is based on the density functional theory, with norm-conserving nonlocal pseudopotentials and nonequilibrium Green's functions. Eight Au-molecule-Au open systems are constructed and numerically examined, where gold atoms are used as electrode, benzene and borazine as core molecules, and sulphur (S), oxygen (O), selenium (Se), and cyano-group (CN) as terminal groups. Gold electrodes are described through a three-dimensional atomic model. The current-voltage (-) characteristics, density of states, and transmission functions of constructed systems are calculated and analyzed. Results show that the transmission properties of the systems are affected greatly by the terminal groups and are dependent on the core molecule as well. Se is demonstrated as the best terminal group to couple borazine to Au electrodes and CN is the best one to couple benzene to Au electrodes.
Proceedings of the 1997 1st Electronic Packaging Technology Conference (Cat. No.97TH8307)
Processes with potential for low cost flip-chip on board assembly were investigated in order to p... more Processes with potential for low cost flip-chip on board assembly were investigated in order to populate conventional printed circuit cards directly or to replace wire bonding in ball grid array packages. Overall aspects of wafer bumping, device placement, underfill encapsulation and assembly integrity were addressed. Two types of wafer bumping process were evaluated, involving fine pitch stencil printing of solder
International Journal of Nanoscience, 2005
We have studied the metal-molecule interface linkage effects of metal-molecule-metal systems by f... more We have studied the metal-molecule interface linkage effects of metal-molecule-metal systems by first principles method, which is based on density functional theory (DFT) and nonequilibrium Green's functions (NEGF) to calculate the electron transport of open metal-molecule-metal systems. Metal electrodes are described through 3-D atomic model instead of a non-atomic (like Jellium model) description. Several open systems are constructed, optimized and simulated. Sulphur atom (S) and cyano-group (CN) are employed to connect Au electrodes and molecule borazine/benzene. The density of states (DOS) and the transmission functions (TF) of constructed systems are investigated. Results show that DOS of the systems are affected little but transmission properties a lot by terminal groups CN and S. The peaks in the TF mismatch with those in DOS and the mismatch resulting from terminal group CN is larger than it from terminal atom S. Calculated transmission functions show that the systems wi...
Proceedings of the 5th Electronics Packaging Technology Conference (EPTC 2003)
Processes for producing tantalum pentoxide thin film capacitors and tantalum nitride thin film re... more Processes for producing tantalum pentoxide thin film capacitors and tantalum nitride thin film resistors in a combined process flow with multi-level interconnects are demonstrated, as may be applied to wafer level packages or thin film modules. Considerations of materials property and component parameter relations are presented in order to fabricate stable, high tolerance devices. Process capability indices are discussed, based
2006 IEEE Conference on Emerging Technologies - Nanoelectronics
... molecules, Nature, Vol. 403, pp.635-638, 2000. [11] W. Tian, S. Datta, AHARONOV-BOHM-TYPE E... more ... molecules, Nature, Vol. 403, pp.635-638, 2000. [11] W. Tian, S. Datta, AHARONOV-BOHM-TYPE EFFECT IN GRAPHENE TUBULES - A LANDAUER APPROACH, Phys. Rev. B, Vol. 49, pp.5097-5100, 1994. [12] H. Mehrez ...
2006 Sixth IEEE Conference on Nanotechnology
We investigate the electron conductance of thiophene oligomers based molecular wires using the fi... more We investigate the electron conductance of thiophene oligomers based molecular wires using the first principles method, which is based on the density functional theory and nonequilibrium Green's function. The molecular wires are built by bridging various thiophene oligomers (dimers, tetramers and hexamers with different inter-ring torsional angles) between two gold electrodes via terminal groups S and CN. The projected energy levels, energy gaps, transmission functions and current-voltage characteristics of the molecular wires are calculated and analyzed. Results show that the molecular wires with the planar structures of thiophene oligomers have larger electron transmission functions, hence better electronic conductance than those with twist structures. The conductance of molecular wires decreases when the chain length of the thiophene oligomer increases. The terminal groups between the oligomer and the electrode has nontrivial effects on the conductance of the wires. The results could provide a qualitative guidance for design molecular electronic wires.
Soldering & Surface Mount Technology, 2002
A challenge in selecting and applying lead‐free solders lies in separating the influences of mate... more A challenge in selecting and applying lead‐free solders lies in separating the influences of materials' properties, fluxes and processes to obtain robust assembly conditions that are compatible with PCB finishes and all component terminations. This paper discusses simple steps towards establishing a lead‐free assembly process. With reference to results of solder paste spread and wetting tests and component solderability tests, some of the current limitations in applying standard test methods to lead‐free evaluations are highlighted.
IEEE Transactions on Nanotechnology, 2005
The effects of terminal groups on the electron transport between metal electrodes and molecule ar... more The effects of terminal groups on the electron transport between metal electrodes and molecule are investigated through metal-molecule-metal systems using the first principles method, which is based on the density functional theory, with norm-conserving nonlocal pseudopotentials and nonequilibrium Green's functions. Eight Au-molecule-Au open systems are constructed and numerically examined, where gold atoms are used as electrode, benzene and borazine as core molecules, and sulphur (S), oxygen (O), selenium (Se), and cyano-group (CN) as terminal groups. Gold electrodes are described through a three-dimensional atomic model. The current-voltage (-) characteristics, density of states, and transmission functions of constructed systems are calculated and analyzed. Results show that the transmission properties of the systems are affected greatly by the terminal groups and are dependent on the core molecule as well. Se is demonstrated as the best terminal group to couple borazine to Au electrodes and CN is the best one to couple benzene to Au electrodes.