41results about How to "Avoid ablative damage" patented technology

Underfill voids and solder ball defects are detected via laser generation and laser detection of an ultrasonic wave at the top surface of flip chips. High resolution is provided by using small laser spot sizes and closely-spaced laser beams of wavelengths that are absorbed near the surface of the semiconductor. Alternatively, the generation laser beam may be absorbed in the bulk of the semiconductor. Improved spatial resolution and rejection of unwanted scattered waves can be attained by limiting the time frame of the ultrasonic waveform to the time required for the first longitudinal wave reflection from the bottom of the flip chip. The laser beam spacing can be reduced by using overlapping probe and detection beams of different wavelengths. Resolution of less than 100 μm features was demonstrated for silicon flip chips.

The invention relates to a cleaning method for optical elements after precise polishing. The method is especially applied to cleaning K9 glass and fused quartz elements processed through polishing platters by classical methods. The cleaning method includes the specific steps that the optical elements taken down from the platters are soaked in gasoline for over 30 minutes, soaked in carbon tetrachloride for two hours, subjected to ultra-sound treatment for 4-10 minutes in the ultrasound frequency of 40 kHz and 120 kHz successively and washed with 35-45 DEG C deionized water for 30-45 seconds; then the elements are subjected to ultrasound cleaning with an ethanol solution for 4-10 minutes and washed with the 35-45 DEG C deionized water for 30-45 seconds; finally, the elements are subjected to ultrasound cleaning with pure water for 4-10 minutes; and the elements are dried and the required products are obtained. The soaking and ultrasound cleaning methods are combined; organic solvents, inorganic solvents and the deionized water are used as media; the efficiency for cleaning up organic contaminants and polishing powder residual particles on the surfaces of the precisely polished elements is high; acidic and alkaline solutions are not involved in the cleaning process, chemical and physical damages to the surfaces of the elements are avoided, and the damage threshold value under ultraviolet laser irradiation is improved.

The invention relates to a heat protection method for an injection support plate of a scramjet engine by utilizing sweat and impingement cooling. The method includes the following steps that (1) a high-temperature-resistant material is used for making the injection support plate of a microporous structure, a supporting rib is arranged in the injection support plate and partitions the same into a front cavity and a rear cavity, impingement pores communicated with the front and rear cavities are formed in the supporting rib, and a fuel pipe of the scramjet engine is communicated with the rear cavity of the injection support plate; (2) by the process that fuel seeps out of pores of the injection support plate of the microporous structure, convection heat transfer is carried out forcedly to remove heat on the surface of the injection support plate, and the fuel seeps out of the surface of the injection support plate to form a film layer so as to block heat transfer of the mainstream to the injection support plate; (3) the fuel is injected from the rear cavity to the inner surface of the front cavity via the impingement pores in the supporting rib so as to perform convection heat transfer with the inner surface of the front cavity, and strength of the injection support plate is enhanced by the aid of the supporting rib in the injection support plate. Heat protection effect on the injection support plate is realized by combining the concept of impingement cooling and utilizing the fuel as a cooling agent according to porous medium characteristics, and the method can be widely applied to heat protection of injection support plates of scramjet engines in various Mach working ranges.

The invention relates to a thermal protection method for a scramjet engine fuel injection supporting plate by the utilization of transpiration cooling. The method includes the following steps that (1), high temperature resistant material is used for manufacturing the injection supporting plate of a multi-tiny-hole structure, and a fuel pipe of a scramjet engine is communicated with the injection supporting plate; (2), by the utilization of the process that fuel leaks through holes of the injection supporting plate of the multi-tiny-hole structure, and heat convection is performed forcibly, so that the heat on the surface of the injection supporting plate is taken away; (3), it is utilized that the fuel leaks through the surface of the injection supporting plate to form a thin layer, so that main flows are prevented from performing heat transfer on the injection supporting plate. The multi-tiny-hole structure is manufactured on the injection supporting plate material, the concept of transpiration cooling is used, the fuel serves as a cooling agent, so that strong heat convection happens between the fuel and the injection supporting plate in the process that the fuel flows through the injection supporting plate, meanwhile, the fuel forms the thin layer on the surface of the injection supporting plate, heat transfer between the high temperature main flows and the surface of the injection supporting plate is obstructed, thermal protection on the injection supporting plate and particularly the front edge part of the injection supporting plate is achieved, and the injection supporting plate is prevented from being ablated and damaged. The thermal protection method can be widely applied to thermal protection performed on various ramjet injection supporting plate structures.

The invention discloses a semi-automatic magnetic tile tensioning device, comprising a positioning plate and a tensioning mechanism. The tensioning mechanism includes a bottom plate, a guide seat, a positioning base, a locking block, a cylindrical pin, an elastic reset device and an upper die. The seat is sleeved on the upper part of the guide seat, the upper end of the guide seat is provided with an outer conical part, the inside of the positioning base is provided with a second circular hole at a corresponding position, and the outer side wall of the upper end of the second circular hole is provided with N square holes that are evenly distributed around the circumference. A locking block is inserted into the square hole, which can be connected with the square hole to move along a radial line. The inner side of the locking block is provided with an inner conical arc surface that matches with the outer conical part. The elastic reset device is arranged on the positioning base and the guide. between seats. In the present invention, the press drives the upper die to go down, the upper die drives the workpiece and the positioning base to go down together, drives a plurality of locking blocks to move downward and outward at the same time, and tensions the corresponding magnetic tiles, which ensures the uniform thickness of the glue and improves the magnetic properties. The bonding strength of the tile can effectively avoid the phenomenon of scratching between the rotor and the stator.

The invention provides a circuit breaker and a remote control miniature circuit breaker. The circuit breaker comprises a handle spring used for handle resetting. The hand spring is connected in series in one circuit loop of the circuit breaker. One end of the handle spring is connected with one end of the circuit loop. The moving end of the handle spring is contacted with and separated from the other end of the circuit loop along with the closing and separating action of the handle so as to realize connection and disconnection of the circuit loop. The scheme of applying the handle spring to the circuit loop can be used for a remote control miniature circuit breaker comprising an N-pole circuit breaking unit and a P-pole circuit breaking unit, and the handle spring of the N-pole circuit breaking unit or the P-pole circuit breaking unit is connected in series in the power loop of the control circuit board of the N-pole circuit breaking unit. The moving end of the original handle spring of the circuit breaker is configured as the structure of a moving contact end which is also used for performing connection and disconnection of the line so that the structure is simple, the design is ingenious, processing and assembling are easy and the circuit breaker has great economy.