Ormet Corporation

Lutz W Brandt

Pradeep R Gandhi

Xiaomei Xi

Goran S Matijasevic

Bryan Shearer

Goran Matijavesic

Sam Fu

Linh Ha

Catharine Gallagher

A method for cost-effectively producing thermoelectric elements and thermoelectric modules with a multitude of thermoelectric couples is disclosed. This method makes the fabrication of very small size thermoelectric elements and miniaturized, compact, powerful thermoelectric modules possible. Methods of the present invention can be also used to fabricate integrated thermoelectric modules in electrical or other devices. The invented method is based on an additive technology using thermoelectric pastes and a patternable insulator layer. Layers of conductive traces are first fabricated on the two insulating planes. A patternable insulator layer is formed and filled with P- and N-type thermoelectric pastes. The thermoelectric elements are formed during the curing or sintering of the thermoelectric pastes. Sizes and positions of the thermoelectric elements are defined by the patterned insulator layer. Thermoelectric modules are obtained by electrically connecting the P- and N-type thermoelectric elements through the electrical conductive traces on the two insulating planes.

Process for producing high performance thermoelectric modules

A method of fabricating individual, embedded capacitors in multilayer printed circuit boards is disclosed. The method is compatible with standard printed circuit board fabrication. The capacitor fabrication is based on a sequential build-up technology employing a first patternable insulator. After patterning of the insulator, pattern grooves are filled with a high dielectric constant material, typically a polymer/ceramic composite. Capacitance values are defined by the pattern size, thickness and dielectric constant of the composite. Capacitor electrodes and other electrical circuitry can be created either by etching laminated copper, by metal evaporation or by depositing conductive ink.

Individual embedded capacitors for laminated printed circuit boards

In accordance with the present invention, there are provided novel metal-containing compositions useful for the preparation of electrical resistance devices (e.g., resistors and thermistor elements). Compositions according to the invention comprise at least one low melting point metal material, and optionally a higher melting point metal material, with the further presence of a binder system also being optional. Compositions according to the invention exhibit a wide range of resistivity and a wide range of values for temperature coefficient of resistance (TCR). Compositions with low values for TCR are useful for resistor applications while compositions with large values for TCR are useful for thermistor applications. Resistor or thermistor elements can be produced by applying compositions according to the invention onto suitable substrates and subsequently alloying (i.e., curing and/or sintering) the compositions. During curing/sintering, the metal or metal alloy powders undergo transient liquid phase sintering to form a continuous metallurgical network. The electrical conduction of the resulting resistor and/or thermistor elements is achieved as a result of the continuous metallurgical network. Resistance and values for TCR of resistors and/or thermistors prepared employing compositions according to the invention are dependent on the intermetallic compounds formed as a result of the alloying/sintering process. Resistors and thermistor elements formed employing compositions according to the invention are stable up to approximately 250.degree. C. and can be used in the temperature range of about -50.degree. C. up to about 200.degree. C. These metal-containing compositions are compatible with polymer, metal and other types of substrates, are highly reliable as compared to existing technology.

Metal-containing compositions and uses thereof, including preparation of

In accordance with the present invention, it has been discovered that conductive traces made from transient liquid phase sintering (TLPS) pastes, plated by electroless or electrolytic means, result in improved solderability, adhesion and conductivity of the circuitry. Transient liquid phase sintering pastes employed in the practice of the present invention differ from conventional metal loaded polymer thick film (PTF) inks in that they contain, in addition to a binder, they also contain both a relatively high melting metal powder and a relatively low melting solder powder capable of forming a continuous intermetallic/metallic phase after sintering. The present invention is particularly useful, for example, for the fabrication of single and multi-layer printed circuit boards, providing horizontal and vertical conductive interconnects, metallized through-holes, and conductive pads for electronic component attachment.

Growing community of inventors

Carlsbad, CA, United States of America

Lutz W Brandt