摘要:
When soldering semiconductor devices in a solder reflow furnace flux is vaporized and carried to the furnace exhaust pipe. The flux condenses on the walls of the exhaust pipe and drips back into the furnace contaminating production parts. A solder reflow furnace with a flux effluent collector prevents flux drip-back. The flux effluent collector has an exhaust gas heater that maintains flux effluent in a gaseous state, a flux cooler, to subsequently condense flux, and a flux condensation region where the flux condenses. The flux condensation region is offset from the furnace's exhaust opening so that condensed flux cannot drip back into the furnace.
摘要:
An organic carrier member for mounting a semiconductor device is provided that has a plurality of solder pads containing low amounts of tin and bismuth. Embodiments include a bismaleimide-triazine epoxy laminate having a plurality of solder pads on the surface thereof where the solder pads contain no more than about 20 weight percent tin and has a reflow temperature of no greater than about 270° C.
摘要:
A method of assembling a substrate and die in a flip chip configuration using a no clean flux. The no clean fluxes have sufficient chemical activity to activate solder bumps contacting bond pads to form reliable solder joints, sufficient tackiness to hold the substrate and die in alignment with the solder bumps contacting the bond pads, and a viscosity to enable a high volume manufacturing process to be used. The no clean fluxes leave a minimal amount of residue during a reflow process that does not interfere with an underfill operation and does not adversely affect the solder joints. The no clean fluxes that can be used for this application are RM1919 from Alpha Metals, Co. and H208 from Indium Company.
摘要:
An automated method of applying flux to substrate on which a semiconductor chip is to be assembled in a flip chip configuration by applying a controlled amount of flux to the substrate by a brush that applies the flux to the substrate in a programmed pattern of strokes thereby overcoming the surface tension of the flux/substrate surface. The programmed pattern of brush strokes is determined empirically for the specific combination of substrate and chip that is being assembled and is thus repeatable and operator independent. The empirically determined program also determines the amount of flux that will be applied to the substrate for the specific combination of substrate and chip being assembled. The empirically determined program is applied to a mechanical stage that moves the brush and to a flux reservoir by a CPU.
摘要:
An apparatus and method to vertically route and physically pass multiple optical fibers through the walls of a package. One variation is a method to route an optical fiber ribbon through a wall of a package by routing and securing the width of the optical fiber ribbon perpendicularly to a component within the package. Another variation involves a package having an enclosure with an opening through which a group of optical fibers are arrayed in a rectangular cross-section with a width which is longer than a thickness. The package includes a component inside the enclosure, a group of optical fibers routed through the opening to the component where the width of the rectangular cross-section is perpendicularly oriented to the base of the enclosure, and a clamp to secure the width of the rectangular cross-section of the group of optical fibers perpendicularly to the base of the enclosure.
摘要:
Apparatus and methods to metallize, reinforce, and hermetically seal multiple optical fibers are described herein. A ribbon of optical fibers may be placed into a fixture to expose a mid-span segment for removal of the coatings from the optical fibers by acid etching, laser, etc. A variety of metallic coatings may then be deposited onto the bare segment of the optical fibers. The metallized segment of optical fibers are then deposited with solderable alloy onto a plate for attachment to the plate for reinforcement of the metallized segment. The plate and metallized segment is then fed through a package opening and hermetically sealed to internally connect one or more components inside the package by heating the package to melt additional solder around the opening or gap. Epoxy is then applied over the solder to help protect the solder and additionally seal the package.