Hughes Aircraft Company

Other

Beckman Instruments, Inc.

William A Vitriol

Gary W Johnson

Raymond L Brown

Alan L Kovacs

Ramona G Pond

Clifford L Shock, Jr

Frank A Ruegg

Low temperature, co-fired ceramic (LTCC) modules (10, 80, 82, 110, 102, 140, 160) are interconnected to one another, stacked and automatically connected to other modules by rigid LTCC interconnecting modules (104), or provided with covers or hermetically sealed covers (130, 166) that automatically register and make electrical or mechanical connections between the cover and the protected module. The various types of connections are achieved by forming in the LTCC modules, during the lamination process, patterns of frictionally interfitting bumps (60, 62, 66, 84a, 84b, 84c) on one side and depressions (70, 72, 76, 81a, 81b, 81c) on the other, whereby a pattern of bumps on one side of one module will connect both mechanically and electrically to a mating pattern of depressions on the other module to stack and automatically lock vertical packages of LTCC modules. The concept is applicable to an LTCC test board (120) at which a module (124) to be tested may be registered and connected to a test board and then tested and readily removed without time consuming registration and connection, and allowing reuse of the test board.

Circuit module connections

A lid (2) for an electronic circuit housing (4) has inner (24) and outer (22) laminated layers that are formed from two different materials, joined to each other and bowed outward from the housing (4) so that the inner layer (24) is under tensile bending stress at the interface between the layers, and the outer layer (22) is under compressive bending stress at the interface. This forms a pre-stress on the lid that resists external loads, and causes the lid to deflect under loading in a linear, predictable and recoverable fashion. The lid is preferably formed by thermal bonding of two materials having different coefficients of thermal expansion, with the bow forming as the materials cool. In one example two different metals are used, and in another a metal is bonded to a glass-ceramic tape.

Pre-stressed laminated lid for electronic circuit package

An electrical circuit pattern is formed on a glass-ceramic, thermally fusible tape. The tape is heated to a temperature at which it becomes temporarily plastic, and is then bent into a desired non-planar shape. Further application of heat causes the tape to be sintered in the non-planar shape. A multi-layer structure can be provided by laminating plural layers of Low-Temperature-Cofired-Ceramic (LTCC) tape with respective circuit patterns formed thereon together, and plastically bending the laminated structure into the non-planar shape during the heating step. A circuit structure including an edge connector can be formed by laminating a layer of glass-ceramic transfer tape having an electrical circuit pattern which includes conductor strips formed on an edge connector portion thereof onto a relatively rigid substrate, such that the edge connector portion is bent around an edge of the substrate to form a rigid edge connector. The edge connector portion of the transfer tape which is formed into a non-planar shape during the lamination step, is fused together with the remaining portion of the transfer tape onto the substrate during the heating step.

Three dimensional microcircuit structure and process for fabricating the

A structure formed of a plurality of sheets which are laminated and fused together includes at least one sintered ceramic sheet formed from thermally fusible tape. A sensor element, such as a cantilever, circular diaphragm, rectangular diaphragm supported at least two sides, or microbridge, is formed as a part of the ceramic sheet. A hole may be formed through one of the sheets adjacent to the ceramic sheet to expose the sensor element to an ambient environment which is to be sensed. Electrical signals corresponding to a physical change in the sensor element such as stress or displacement are generated by piezoresistor, variable capacitor, photodetector, or the like attached to or formed on the sensor element, which is interconnected with a metallization pattern formed on at least one of the sheets. The thickness of the sheets is highly uniform, thereby producing sensor elements with precisely reproducible thicknesses and mechanical properties.

Sensor elements in multilayer ceramic tape structures

A technique is disclosed for trimming resistors and other passive circuit components buried in hybrid multilayer circuit structures. For example, resistors (13) are formed between two dielectric layers (11, 19) of a hybrid multilayer circuit structure (10). The multilayer circuit structure with the buried resistors is appropriately processed to provide a fired multilayer circuit structure. Trimming of the buried resistors is accomplished with a laser beam that cuts through dielectric material of the fired circuit structure to selectively remove part of the resistive material of the buried resistors. The values of the buried resistors may be tested with conductive elements (15, 17) that are conductively coupled to the buried resistors. The disclosed technique also contemplates the trimming of other buried passive circuit components such as capacitors, and further contemplates the use of other trimming methods such as abrasive, air jet, or water jet trimming.

Trimming passive components buried in multilayer structures

We disclose a process for manufacturing multilayer circuit boards which includes providing a conductive, or an insulating substrate with a conductive pattern thereon, and then transferring and firing a glass-ceramic tape layer to the surface of the substrate. This tape layer provides both electrical isolation between the substrate and electrical conductors or electronic components which are subsequently bonded to or mounted on the top surface of the glass-ceramic tape layer. By providing vertical electrical conductors by means of vias in the tape layer prior to firing the tape layer directly on the substrate, good X and Y lateral dimensionally stability of the tape material is maintained. In addition, a high quality thick film glass-ceramic electrical interconnect structure is achieved at a relatively low manufacturing cost.

Process for fabricating dimensionally stable interconnect boards

A screen printed capacitor to provide a predetermined temperature coefficient of capacitance. The capacitance device utilizes a common electrode with a uniform dielectric layer in conjunction with two side-by-side base electrodes resulting in opposite polarity temperature coefficient of capacitance values. The proportion of the area of each of the side-by-side base electrodes with respect to each other determines the predetermined temperature coefficient of capacitance required.

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Anaheim, CA, United States of America

William A Vitriol