1. A heat sink for cooling a semiconductor device, comprising:
plural base members, the base member being each in plate or block-shape, the base member each having paths shaped on one or both sides of surfaces thereof, and the base members being bonded to each other;
a coating layer of Au being onto the members; and
a bond layer of alloy containing at least 91 wt % of Au and at most 9 wt % of Sn, the bond layer being interposed between connecting regions at which a pair of the base members is bonded,
wherein the paths shaped on surfaces of the base members are connected to each other to form a communicating flow path for a cooling medium inside the bonded base members.
2. The heat sink according to claim 1, wherein the base members are made of at least one material selected from the group consisting of Cu, Cu\u2014W type alloy, Mo, Fe\u2014Ni\u2014Co type alloy, aluminum nitride and silicon carbide.
3. The heat sink according to claim 1, further comprising a semiconductor device, wherein the semiconductor device is one selected from the group consisting of a single laser emitter, a laser diode array having plural laser emitters aligned in an array form, various types of transistors, and an integrated circuit.
4. The heat sink according to claim 1, further comprising a coating layer of Ni being onto the base members, the coating layer of Ni being overlaid with the coating layer of Au.
5. A method for producing a heat sink for cooling a semiconductor device, comprising the steps of:
forming plural base members, the base member being each in plate or block-shape, the base member each having paths shaped on one or both sides of surfaces thereof, and the base member each having connecting regions on one or both sides of surfaces thereof;
coating a coating layer of Au onto the base members;
putting a solder of Sn or Au\u2014Sn alloy onto connecting regions, the connecting region being coated with the coating layer of Au;
assembling the base members together such that the base members are bonding to each other at the connecting region and the paths shaped on each of the surfaces of the base members form a communicating flow path for a cooling medium inside the bonded base members; and
heating to diffuse Sn from the solder of Sn or Au\u2014Sn alloy into the coating layer of Au, and to make a bond layer of alloy containing at least 91 wt % of Au and at most 9 wt % of Sn, the bond layer being interposed between connecting regions to which the base member each connects.
6. The method according to claim 5, further comprising a step of: coating a coating layer of Ni onto the base members, wherein the coating layer of Ni is overlaid with the coating layer of Au.
7. The method according to claim 5, wherein a solder of Sn or Au\u2014Sn alloy is in a form of sheet or in vapor phase, and the heating is performed at a temperature not lower than a liquidus line of the solder.
8. The method according to claim 5, further comprising the steps of:
making a coating layer of the solder of Sn or Au\u2014Sn alloy, when the solder of Sn or Au\u2014Sn alloy being put onto connecting regions, such that the coating layer of the solder of Sn or Au\u2014Sn alloy overlays the coating layer of Au; and
pressing a pair of the base members toward each other, when heating,
wherein the heating is performed at a temperature not lower than a liquidus line of the solder.
9. The method according to claim 5, further comprising the steps of:
pressing a pair of the base members toward each other, when heating,
wherein the heating is performed at a temperature of 280 to 600\xb0 C. for 1 to 120 minutes, and the pressing is performed at a pressure of 0.1-10 Mpa.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of driving an image display device, the image display device comprising:
a display panel configured to display an image; and
a diffractive element including:
a first substrate and a second substrate facing each other,
a first electrode layer disposed on the first substrate,
a second electrode layer formed on the second substrate, and
a liquid crystal layer interposed between the first substrate and the second substrate,
the method comprising:
operating the diffractive element in a 2D mode or a 3D mode so that the image of the display panel is perceived as a 2D image or a 3D image after passing through the diffractive element,
wherein the operating of the diffractive element in the 3D mode includes applying a common voltage to the second electrode layer and applying voltages to the first electrode layer wherein a polarity of the voltage applied to the first electrode layer of a first zone with respect to the common voltage is different from a polarity of the voltage applied to the first electrode layer of a second zone adjacent to the first zone with respect to the common voltage.
2. The method of claim 1, wherein:
operating the diffractive element in the 3D mode includes operating the diffractive element having further includes a plurality of unit lenses.
3. The method of claim 2, wherein:
each of the plurality of unit lenses operates as a Fresnel zone plate.
4. The method of claim 3, wherein:
each of the plurality of the unit lenses includes a plurality of the zones sequentially positioned to the outside about a center of the unit lens.
5. The method of claim 1, wherein:
the first electrode layer includes at least one first electrode and at least one second electrode.
6. The method of claim 5, wherein:
the liquid crystal layer includes liquid crystal molecules each having a director, and
the liquid crystal molecules are aligned so that a phase delay of light beams passing through the liquid crystal layer in each of the first and second zones changes in a step-wise fashion across each zone.
7. The method of claim 6, wherein:
each of the first and second zones includes one or more subzones corresponding to positions of the first and second electrodes, and the liquid crystal molecules are aligned for causing the same phase delay to the first electrodes or the second electrodes corresponding to the same subzones of the plurality of zones.
8. The method of claim 5, wherein:
the liquid crystal layer includes liquid crystal molecules each having a director, and
the liquid crystal molecules are aligned so that in each of the first and second zones, the liquid crystal molecule alignment changes across each zone in a step-wise fashion.
9. The method of claim 8, wherein:
the widths of the at least one first electrode and the at least one second electrode in each of the first and second zones increase across each zone.
10. The method of claim 8, wherein:
in each of the first and second zones, the at least one first electrode and the at least one second electrode are configured to receive voltages so that differences between the voltages applied to the at least one first electrode and the at least one second electrode and the common voltage gradually decrease across each zone.
11. The method of claim 10, wherein:
in the first electrode layer, a voltage difference dV between voltages applied to two electrodes adjacent to each other at the boundary of the first and second zones is set by a difference dVmax between a first voltage applied to an electrode of each zone positioned closest to an outer position with respect to the center of the unit lens and a second voltage applied to an electrode of each zone positioned closest to a position nearest the center of the unit lens, and an offset voltage Voffset which is a difference between the second voltage and the common voltage.
12. The method of claim 11, wherein:
in the first electrode layer, the voltage difference dV between voltages applied to the two electrodes adjacent to each other at the boundary of the zones satisfies
dV=dVmax+2Voffset.
13. The method of claim 10, wherein:
in the first electrode layer, a voltage difference dV between voltages applied to two electrodes adjacent to each other at the boundary of zones is set so that transmittance of a zone boundary portion becomes a predetermined value or less.
14. The method of claim 10, wherein:
an interval between two electrodes adjacent to each other at a boundary zone of the first and second zones and a cell gap are set so that transmittance of the zone boundary becomes a predetermined value or less.
15. The method of claim 5, wherein:
each of the first and second zones includes two first electrodes and two second electrodes on the fist electrodes, the two first and two second electrodes are insulated from each other.
16. The method of claim 5, wherein:
each of the first and second zones includes two first electrodes and one second electrodes on the two first electrodes, the one second electrodes is insulated from the two first electrodes or includes one first electrode and two second electrodes on the one first electrode, the two second electrodes are insulated from the first electrode.
17. The method of claim 16, wherein:
edges of a first electrode and a second electrode adjacent to each other do not overlap each other.
18. The method of claim 1. wherein:
operating the diffractive element in the 2D mode includes causing the diffractive element to transmit the image displayed on the display panel as it is.
19. The method of claim 18, wherein the image display device further comprises comprising:
an alignment layer configured to align liquid crystal molecules of the liquid crystal layer.
20. The method of claim 1, wherein:
the second electrode layer of the first zone is connected to the second electrode layer of the second zone.
21. The method of claim 1, wherein when the first electrode layer of the first zone is applied with a positive voltage with respect to the common voltage, the first electrode layer of the second zone is applied with a negative voltage with respect to the common voltage or the common voltage.