摘要:
This invention relates to soldering systems of the type that provide localized soldering through the use of lasers. Such structures of this type generally allow flexible printed circuit boards to be locally soldered to metallized ceramic substrates. These structures have applications in such areas as ultrasound equipment.
摘要:
A piezoelectric ultrasonic array transducer has its individual elements connected to external electronics via a high density interconnect structure which facilitates signal connection and uniformity from array-to-array. The array fabrication process is preferably modified for use with a high density interconnect structure in order to obtain maximum transducer quality.
摘要:
An ultrasonic imaging system probe with an even-number of transducer elements, has a transformer for coupling the received signal from each transducer to an associated cable. The polling of the transformer primary windings are identical while the polling of the secondary windings of the transformer alternate, i.e. are reversed for all even-numbered channels, with respect to odd-numbered channels. All odd channel outputs are conected to a first signal bus, while all even channel outputs are connected to a second signal bus. The signal busses are connected to inputs of a differential-input amplifier, having an output which provides the sum of all channel transducer outputs, with suppression of any common-mode signal appearing in the system from the channel transformer secondary windings to the differential amplifier inputs.
摘要:
An ultrasonic transducer has two impedance matching layers bonded to the transducer element which have different thicknesses and are 90.degree.-100.degree. and 35.degree.-55.degree. matching layers. This structure has a high sensitivity comparable to a broadband front surface matched transducer with quarter wavelength (90.degree. and 90.degree.) matching layers, and has primarily a single resonant mode so as to be suitable for relatively narrow band applications.
摘要:
A cryogenic solid-state semiconductor power device, has the actual device chip mounted on a substrate of a material of very high thermal conductivity, which is positioned in a a bath of cryogenic fluid. The substrate may be formed of beryllia, beryllium, alumina, aluminum nitride, diamond and the like materials.
摘要:
A slab of piezoelectric ceramic plated on all surfaces is bonded to quarter wavelength impedance matching layers of glass and plastic. The top surface of the ceramic is slotted and parallel cuts orthogonal to the slots are made through the ceramic and into the glass to delineate an array of elements each with a signal electrode between slots and a wrap-around ground electrode. After making ground connections and flying lead connections to the signal electrodes, the matching layers are fully cut through from the front. A covering or wear plate is attached to the front surface and a relatively large mass of acoustic damping material covers the backs of the elements.
摘要:
A piezoelectric or electrostrictive composite exhibiting anisotropic 3-3 connectivity with a dense ceramic phase and an infiltrate polymer phase. The ceramic phase is an interconnected ceramic lamelli structure that is arranged substantially parallel in one direction. The ceramic lamelli have greater connectivity in the z direction than in the x and y directions, while the connectivity in the x and y directions are essentially equal.
摘要:
An ultrasonic imaging system has a probe with an even-numbered plurality of N of transducer elements, with one transducer element being present in each of a like plurality N of signal-processing channels, and with successive ones of the transducers polarized in alternating directions. The transducers require channel excitation drive signals which are either a positive-polarity pulse or a negative-polarity pulse, with signal polarity being dependent upon the polarity of the transducer in the particular channel. The processed outputs of each odd channel is connected directly to an associated input of a coherent summer while the processed output of each even channel is individually amplitude-inverted before connection to an associated summer of input. The summation means output is the sum of all channel transducer outputs, with suppression of any common-mode signal appearing anywhere in the system channels, from the transducer to the summation means inputs.
摘要:
Power line interference artifacts in a magnetic resonance image are minimized by the process of: providing a sequential plurality of imaging signal sequences, the totality of which sequences is required for determining the value of each image pixel in an image array thereof; requesting the start of each sequence of the plurality of imaging signal sequences prior to the actual time at which each such signal sequence should commence; preparing a recognition element prior to the desired actual commencement time; recognizing a predetermined occurrence of a repetitive power line signal parameter to provide a first signal; setting the recognition element responsive to the first signal to only then cause the signal sequence start request to actually cause commencement of the associated signal sequence; and causing each signal sequence to occur in essentially an integral number of sequential repetitive cycles of the power line signal waveform to minimize the magnitude of power line frequency signal interference artifacts in the resulting magnetic resonance image.
摘要:
A linear transducer array for 90.degree. or other wide angle sector scans is covered by a body contacting wear plate made of a material such as filled silicone rubber or polyurethane epoxy in which the longitudinal sound velocity is equal to or less than that in the body and in which the acoustic impedance for longitudinal sound waves is approximately equal to that of the body. Refraction, if it occurs, enhances the field of view without reducing the transmission of acoustic energy. The wear plate provides mechanical support for a fragile front surface matched array.