Motorola Corporation

Vahid Kazem-Goudarzi

Kingshuk Banerji

Edwin L Bradley, Iii

William B Mullen, Iii

Kiron P Gore

Henry F Liebman

Alex Marron

Edward J Hall

Sterling T Holmes

Val Jean Hillman

Hai Teo

A method and apparatus for detecting whether a vacuum nozzle on a high speed component placement machine is obstructed. A vacuum nozzle (10) has a hollow tube with a vacuum port (25) and an opening (12) at one end. A plastic light guide is connected to the vacuum nozzle such that one portion of the light guide is exposed to be illuminated (50) by a remote light source (30). The light guide transmits light to illuminate the opening (12) from the interior of the vacuum nozzle. The amount of light exiting the illuminated opening is measured (55) by a remotely located light detector (35). A decision (60) is made as to whether the opening is obstructed by comparing the measured illuminated opening to a predetermined standard.

Method and apparatus for detecting obstructed vacuum nozzles

A method of detecting whether a vacuum nozzle on a high speed component placement machine is obstructed. A vacuum nozzle (10) has a hollow tube with a vacuum port (25) and an opening (12) at one end. The hollow tube having a fiber optic wire (20) located within it such that one end of the fiber optic wire is exposed to be illuminated (50) by a remote light source (30). The fiber optic wire transmits light to illuminate the opening from the interior of the vacuum nozzle. The amount of light exiting the illuminated opening is measured (55) by a remotely located light detector (35). A decision (60) is made as to whether the opening is obstructed by comparing the measured illuminated opening to a predetermined standard.

Method for detecting obstructed nozzles

A soldering process using two different types of solder alloys is disclosed. The first solder alloy (115) undergoes a solid-to-liquid transition at a first temperature. The second solder alloy (120) undergoes this solid-to-liquid transition at a second temperature, the second temperature being greater than the first temperature. The soldering composition is deposited (20) on a substrate (100) having solderable portions (105) and is heated to a temperature that is above the first temperature but below the second temperature (32). During this time, the first solder alloy liquifies, while the second solder alloy remains solid. The soldering composition is subsequently cooled (40) to solidify the first solder material. A part or electronic component is added (80) to the solidified solder material and the solder materials is again heated above the second temperature (30) in order to reflow the solder and form a metallurgical bond between the substrate and the electronic component.

Soldering process

A soldering process uses two or more different solder alloys. A first solder alloy (115) that undergoes a solid-to-liquid transition at a first temperature is coated (20) onto the solderable surfaces (105) of a printed circuit board (100). A solder paste (120) that undergoes this solid-to-liquid transition at a temperature greater than the first temperature is deposited on the coated solderable potions, and is heated to a temperature that is above the first temperature but below the second temperature. During this time, the first solder alloy liquifies, while the solder paste does not. The first solder alloy wets to the individual particles in the solder paste, and alloys to the solderable surfaces and the solder particles in the solder paste. The soldering composition is subsequently cooled (40) to solidify the first solder material, forming a solid and substantially planar coating on the solderable potions of the printed circuit board.

A solder preform (250) has solder particles of one alloy (210) arranged within a matrix of a second solder alloy (200). This arrangement forms a structure having the desired predetermined shape of the solder preform. The solder particles comprise one or more of the following elements: tin, lead, bismuth, indium, copper, antimony, cadmium, arsenic, aluminum, gallium, gold, silver. The particles have a predetermined melting temperature. The second solder alloy is compositionally distinct from the solder particles, and has a melting temperature that is lower than the melting temperature of the solder particles. The solder particles may comprise about 88% by weight of the solder preform, and the second solder alloy comprises about 12% by weight of the preform.

Multiple alloy solder preform

A solder-clad printed circuit board (100) has solder particles of one alloy (120) arranged within a matrix of a second solder alloy (115). This arrangement forms a flat structure that is alloyed to the solder pads (105) on the substrate. The solder particles (120) have a predetermined melting temperature and are made from one or more of the following elements: tin, lead, bismuth, indium, copper, antimony, cadmium, arsenic, aluminum, gallium, gold, silver. The second solder alloy (115) is compositionally distinct from the solder particles, and has a melting temperature that is lower than the melting temperature of the solder particles. The solder particles may comprise about 88% by weight, and the second solder alloy may comprise about 12% by weight of the solder cladding.

Solder clad substrate

A method of preparing a component for automated placement is provided. The method includes disposing tacking medium on a substantially transparent member (210); engaging the tacking medium with the component (230); and imaging the component through the substantially transparent member (240).

Method of preparing a component for automated placement

A solder joint inspection system comprises a substrate (60) having at least one solder pad (56), a predetermined amount of solder (54) on the solder pad, and an image fluxing material (52) that fluoresces when an ultraviolet light source (42) is applied to the solder (54) and the fluxing material (52). When an ultraviolet light source is applied to the substrate having a predetermined amount of solder and fluxing material, a visual inspecting device (40) can verify if, in fact, the predetermined amount of solder and fluxing material is present.

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Sunrise, FL, United States of America

Vahid Kazem-Goudarzi