Abstract: A low noise miniature potentiometer utilizes thick film deposits of resistive material which extend adjacent to deposits of conductive material. The conductive region is sliced into a plurality of spaced-apart conductive elements. Electrical paths through resistive elements can be lengthen by laser trimming of the resistive material thereby providing for very precise incremental resistances between pairs of spaced apart conductive elements. If desired, an increased range of resistivity can be achieved by utilizing a second deposited thick film region extending along the conductive region and in contact therewith. Laser trimming can be used to increase conductive path lengths in the second resistive element thereby providing a broader range of resistance values.

Abstract: A precision thick film resistor has a deposited thick film conducting layer which is adjacent to and in contact with a deposited thick film resistive layer. A laser scribed line, having a width on the order of 2 mils, separates the conductive region into two parts and then extends into the resistive layer. The value of the resistor is set based on the extent that the line extends into the resistive layer. A plurality of thick film conducting elements can be formed by depositing a continuously extending thick film conducting layer on a substrate. Laser scribed lines can be used to isolate various conducting elements in the deposited film from one another. Elements are separated from one another by 2 mil wide laser scribed lines.

Abstract: A solder bonding technique for bonding discrete circuit elements to conductors on an alumina substrate. The conductors are composed of palladium and silver, and atop each conductor at a bonding site, a layer of silver is provided. A layer of solder is disposed over the layer of silver. The compliancy of the silver layer absorbs stresses created by thermal cycles and thereby improves the peel strength of the solder bond.

Abstract: A semiconductor die is mounted on a metal substrate via intermediate layers which permit the die to be readily soldered to the combination while yet reducing thermal stresses. A dielectric layer is formed over the substrate, followed by another layer of a selected metal, either molybdenum or tungsten. Atop the metal layer is another layer comprising a mixture of solder and the selected metal. A layer of only solder is formed over the mixture, and the semiconductor die is bonded thereto by means of the layer of solder.

Abstract: A pressure sensor assembly includes a pressure transducer having a pressure displaceable diaphragm bonded to a base. Displacement of the diaphragm results in varying of electrical characterisitcs of the transducer in response to sensed pressure. Electrical output connections (wires) of the transducer extend from a central portion of a top surface of the base, which faces the diaphragm, to a central portion of a base bottom surface and peripheral portions of the diaphragm and base top surface are hermetically bonded together. The transducer is mounted on a carrier plate and integral extensions of the electrical output connections pass through holes in the carrier plate. A housing for the sensor assembly has an opening therein to provide access to the diaphragm by ambient atmosphere/fluid surrouding the housing.

Abstract: It has been found that the soldering properties of a wave soldering system can be quantitatively determined by measuring the wickability of the molten solder of the solder bath beyond the areas of direct immersion into the molten solder bath of a solder wave. The test is conducted by providing a test board having a pair of parallel strips of a solderable material such as copper. One of the parallel strips is formed in a continuous length. The other of the parallel strips is formed with discontinuity in the solderable material at regularly predetermined intervals along the length thereof. When conducting the test method of this invention, the test board is partially immersed into the solder wave in the same manner as a printed circuit board assembly, with the parallel strip being in alignment with the machine direction of the wave soldering apparatus. The test board is then removed from the solder wave. The point of maximum direct contact with the solder of the wave is determined from the discontinuous strip.

Abstract: A printing paste vehicle for use in dispensing solids on a substrate comprises at least one polar oxygenated solvent, a binding agent and an organic thixotrope in specified proportions. A solids dispensing paste composition comprises the vehicle, a glass binder and gold in specified proportions. A portion of the paste is deposited in the bottom of a cavity of a microelectronic package, and gradually heated to a temperature sufficient to allow the paste to flow and the gold and glass binder to settle to the bottom of the cavity. The vehicle is volatilized, and the component is subsequently fired to bond the gold to the bottom of the cavity.

Abstract: Multiple pass method of applying printing paste upon a substrate wherein the method includes the application upon a substrate of a printing paste composition containing an inorganic particulate material, a pyrolyzable organic binder and a solvent system for the organic binder which comprises a low boiling temperature solvent and a high boiling temperature solvent. The method includes the steps of applying a first layer of the printing paste composition and the thermal removal of substantially all of the low boiling temperature solvent, but not the high boiling temperature solvent or binder, prior to superimposing the next pass or layer of printing paste having the same characteristics as the first layer thereover. Following the application of the desired number of layers and removal of low boiling temperature solvent in this manner, the high boiling temperature solvent and the binder are thermally removed and the inorganic particulate material is fused to the substrate.

Abstract: The drying characeteristics of a printing paste comprising a vehicle containing a binder and a low boiling point solvent are improved by substituting a high boiling point solvent for a portion of the low boiling point solvent without substantially adversely affecting the viscosity and flow properties of the paste. The printing paste is advantageously employed in silk screen printing in multiple passes where printed layers must have a uniform degree of wetness. The printing paste and vehicle are especially useful in the manufacture of microelectronic packages.