The invention provides a laser beam machining method characterized by comprising the steps of mounting a protective tape (25) on the surface (3) of a wafer (1a), radiating laser light (L) by using the back (21) of a wafer (1a) as a laser light incidence plane with an optical converging point (P) positioned in a substrate (15) to thereby form a melt processing region (13) for melt processing by multiphoton absorption, forming, by means of the melt processing region (13), a cutting start region (8) on the side within a predetermined distance from the laser light incidence plane along a predetermined cutting line (5) on the wafer (1a), mounting an expand tape (23) on the back (21) of the wafer (1a), and stretching the expand tape (23) to thereby separate a plurality of chip-like portions (24) from each other that are formed by the wafer (1a) being cut with the cutting start region (8) used as the starting point.

Laser beam machining method

A laser beam machining method and a laser beam machining device capable of cutting a work without producing a fusing and a cracking out of a predetermined cutting line on the surface of the work, wherein a pulse laser beam is radiated on the predetermined cut line on the surface of the work under the conditions causing a multiple photon absorption and with a condensed point aligned to the inside of the work, and a modified area is formed inside the work along the predetermined determined cut line by moving the condensed point along the predetermined cut line, whereby the work can be cut with a rather small force by cracking the work along the predetermined cut line starting from the modified area and, because the pulse laser beam radiated is not almost absorbed onto the surface of the work, the surface is not fused even if the modified area is formed.

Laser processing method and laser processing apparatus

The invention provides methods and apparatus for nebulizing liquids. In one exemplary embodiment, an apparatus is provided which comprises a thin shell member having a front surface, a rear surface, and a plurality of apertures extending therebetween. The apertures are tapered to narrow from the rear surface to the front surface. A liquid supplier is further provided which delivers a predetermined unit volume of liquid to the rear surface. A vibrator vibrates the thin shell member to eject liquid droplets from the front surface of the thin shell member.

Liquid dispensing apparatus and methods

A novel design of dynamic holographic stereogram with a curved array of spatial light modulators (SLMs) is proposed. In general, it is difficult to simultaneously achieve a wide viewing angle and an available width for the digital holographic display. Moreover, the wide viewing angle of a display system needs a large optical numerical aperture where the paraxial approximation fails, and thus an extremely large planar SLM is necessary in using previous methods. To solve this problem, our proposed display system is composed of a curved array of SLMs to obtain a large number of data points and reduce the spatial bandwidth in SLMs. In the curved array of SLMs, each SLM is individually transformed to display local angular spectra of object wave, which is based on a fundamental idea of holographic stereogram. To embody the dynamic holographic stereogram with SLMs, each SLM is effectively reformed for simplifying the optical structure and reducing the light power loss. In detail, spatially modulated wave is optically divided and transformed, as if each SLM were composed of three sub-SLMs. This design improves the scalability in viewing angle of holographic display and the loss of light power is significantly reduced. With this method, we can achieve the digital holographic display with 22.8 degrees viewing angle.

Wide viewing angle dynamic holographic stereogram with a curved array of spatial light modulators

The present invention recognizes that diagnosis and prognosis of many conditions can depend on the enrichment of rare cells from a complex fluid sample. In particular, the enrichment of fetal cells from maternal samples, such as maternal blood samples, can greatly aid in the detection of fetal abnormalities or a variety of genetic conditions. In addition, the present invention recognizes that the enrichment of rare malignant cells from patient samples, can aid in diagnosis, prognosis, and development of therapeutic modalities for patients.

Methods, compositions, and automated systems for separating rare cells from fluid samples

A process for precision patterning or cutting of a sheet stock, such as an adhesive tape, includes the step of irradiating a surface of a sheet stock with an irradiation source to pattern or cut a part in the sheet stock. The method is particularly useful for precision cutting adhesive members, such as adhesive fluid seals, for an inkjet print cartridge.

Precision laser cutting of adhesive members

Coalescence of a falling droplet with a stationary sessile droplet is studied experimentally. High-speed video images are presented to show coalescence dynamics, shape evolution and contact line movement. Emphasis is put on spread length, which is the length of two coalesced droplets along their original centers. Experimental results have shown that the spread length can be larger or smaller than the ideal spread length, which is the spread diameter of individual droplet plus the center-to-center distance between the two droplets. Three different coalescence mechanisms based on comparing the maximum and the minimum spread lengths to the ideal spread length are identified. Correlations for the maximum and the minimum spread lengths are developed, which can be combined with the coalescence domains to determine the deposition conditions for forming continuous or discontinuous lines.

Coalescence of two droplets impacting a solid surface

An experimental investigation of the rapid formation and collapse of bubbles formed on a micro heater (25×80 μm 2 ) is presented. Short electric pulses in the range of 1 μs to 4 μs are applied to the resistive heater which is immersed in deionized water and generates a heat flux of more than 750 MW/m 2 . A stroboscopic technique with a time resolution of 30 ns and spatial resolution of 2 μm was used to capture the dynamics of the bubble growth and collapse. From the nucleation theory, the nucleation temperatures are close to the kinetic limit of superheat and weakly depends on the heating rate. The velocity, acceleration, and the pressure profiles after the vapor sheet formation are presented

Experimental Study of Bubble Dynamics on a Micro Heater Induced by Pulse Heating

An ink jet printhead is disclosed which has a heater plate containing the heating elements and driving circuitry means monolithographically formed on one surface thereof and the ink flow directing channel structure is formed on the heater plate using a layer of patternable polymeric material which, in one embodiment, is exposed using a mask to define the channel pattern then developed and cured. After curing, the patterned channel structure is polished to provide a smooth coplanar surface and a cover plate with an aperture therein is aligned and bonded to the channel structure to complete the printhead. The aperture serves as both ink inlet and a portion of the ink reservoir. The channels are open at one end and serve as the droplet ejecting nozzles, while the other ends are closed and extend beneath the cover plate aperture to provide a baffled portion of the ink reservoir and prevent cross-talk between the ink channels. In another embodiment, the channels ends opposite the nozzles open into a common recess with the channels walls extending therein to function as baffles and prevent cross-talk.

Ink jet printhead having a low cross talk ink channel structure

A method for fabricating a filter element to prevent contaminants from entering an ink supply inlet of an ink jet printhead. The filter is formed by laser ablation process in which output laser radiation is directed through a mask system or light transmitting system to create a filter hole pattern in a thin film. Slightly tapered holes are formed in the film, and the formed filter element is laminated to the ink supply inlet. The tapered holes provide improved flow/impedance and add increased structural strength.

John R. Andrews

Papers

Precision laser cutting of adhesive members

Coalescence of two droplets impacting a solid surface

Experimental Study of Bubble Dynamics on a Micro Heater Induced by Pulse Heating

Ink jet printhead having a low cross talk ink channel structure

Method of making an ink jet printhead filter by laser ablation