摘要:
An LTCC module includes a base on one or more surfaces for receiving one or more external components to be attached to the module. A base is formed of a plurality of layers of metallization in a predetermined pattern. The layers include an adhesion layer on the LTCC module surface, with one or more intermediate layers, followed by a top layer. The module is fired with each application of the layers at a reduced temperature lower than the normal cofiring temperature of the LTCC module, but of sufficient value to partially sinter the layers. After the last applied top layer, the module is fired once at an elevated temperature to fully sinter the layers.
摘要:
A method of producing an LTCC substrate having improved cavity bondability is disclosed that involves providing a stack of green ceramic tape sheets having a cavity, placing a template having an opening corresponding to the cavity over the stack, placing a stretchable sheet of material coated with graphite or zinc stearate over the template, isostatically laminating the stack to produce an LTCC substrate having a cavity, and removing the template and sheet of stretchable material from the stack.
摘要:
An LTCC (low temperature cofired ceramic) structure which has conductors to which leads are to be bonded for connection to external circuitry. The conductors include additives to promote adhesion to the ceramic layer. The presence of these additives degrade bonding performance. For better bondability of the leads, a pure conductor metal layer, devoid of the additives is placed on the conductors in areas where leads are to be bonded. This pure conductor metal layer may be cofired with the stack of ceramic layers or may be post fired after stack firing.
摘要:
A fabrication process for ferrite toroids which utilizes ferrite ceramic tape having an improved elongation characteristic. The process utilizes a set of rigid mandrels which are employed in the final lamination to support the rectangular cross section of the internal cavity of a respective ferrite tube, thereby reducing stress concentration and permitting the highest lamination pressure to be used in the final step. The mandrels are removed prior to panel densification. The tape and mandrels operate together to minimize cracks and pores in the toroids and provide an added advantage of maintaining high tolerances in the internal cavity dimensions as well as the cavity-to-cavity alignment.
摘要:
A method of forming an LTCC structure having at least one open cavity on each of first and second opposing sides is disclosed that includes the steps of forming a first LTCC structure including a first side having a plurality of cavities and a second side, subjecting the first LTCC structure to a first pressure, forming a second LTCC structure including a first side having a plurality of cavities and a second side, subjecting the second LTCC structure to a second pressure, arranging the first LTCC structure and the second LTCC structure such that the first LTCC structure second side faces the second LTCC structure second side, and subjecting the placed-together first and second LTCC structures to a third pressure to join the first LTCC structure to the second LTCC structure. A product formed by the subject method is also disclosed.
摘要:
This invention relates to new ceramic piezoelectric compositions having superior electrical properties, processes for the preparation of the new piezoelectric composition and applications for the new compositions. Specifically, a solid solution composition of 85.5-87.5 molar percent lead zinc niobate, 9.5-9.7 molar percent lead titanate and 3-5 molar percent of a barium titanate dopant or strontium titanate dopant has exhibited desirable electrical properties. This specific composition is well suited for use in a 3-1 connectivity composite, which can be used as a hydrophone. These compositions may be prepared by oxide sintering techniques utilizing extremely high purity materials, or alternatively, by a sol gel process.
摘要:
A method of fabricating ferrite toroids used in ferrite phase shifters. The method employs fabrication techniques found in low temperature cofired ceramics (LTCC) tape technology and involves fabricating long rectangular through-holes, as is required by the toroid design, in layers of green ceramic tape and maintaining the integrity of the through-holes during a firing process wherein ferromagnetic ceramic oxide in the tape is converted to ferrite.
摘要:
We disclose a fabrication method for integrating passive devices such as capacitors, resistors and circulators into ceramic packages for electronic systems. The method utilizes a glass or glass/ceramic as a bonding agent which is incorporated as one of the layers in the multilayer package. The integration of such passive devices eliminates the tedious mounting of these devices on the package, permitting a smaller, more reliable, less expensive and lighter weight product. This method allows the integration of passive devices having firing temperatures far different from that of the ceramic package itself, permitting combinations of materials that cannot be densified, or cofired together.
摘要:
The invention relates to new ceramic electrostrictive compositions having superior electrical properties, a process for the preparation of the new electrostrictive compositions and applications for the new compositions. Specifically, a solid solution composition of lead magnesium niobate-lead titanate - (barium titanate or stronium titanate) has exhibited desirable electrostrictive properties. This composition shows a diminished dependence of dielectric constant on temperature.
摘要:
Total internal light spatial light modulation apparatus includes a light source for projecting infrared light; a prism for reflecting the projected light from an internal surface therein; and an array of pixel posts made of electrostrictive material and positioned proximate a back face of the internal surface for selectively eliminating pixel areas of reflection of the projected light to form an image thereby. A multiplexer is provided to select a set of pixel posts to be electrically charged which corresponds with the image, and electrical contacts are formed on each pixel post no permit electrical charging of each selected pixel post. Method of fabricating the pixel post array, wherein each row of the pixel post array is formed as a monolithic structure, includes the steps of providing a slab of alternate layers of ferroelectric and electrically-conductive material; vapor-depositing electrical contacts on the slabs in electrical communication with the layers of electrically-conductive material at locations corresponding to the pixel posts to be fabricated; securing the slabs together in a front-to-back relationship with divider plates positioned therebetween; and cross-cutting a number of grooves through the slabs to define the pixel posts of each row.