Cleaning and liquid contact with solids – Processes – Including melting
Reexamination Certificate
1999-08-02
2001-08-21
El-Arini, Zeinab (Department: 1746)
Cleaning and liquid contact with solids
Processes
Including melting
C134S019000, C134S022100, C134S022110, C134S042000
Reexamination Certificate
active
06277206
ABSTRACT:
FIELD OF THE INVENTION
The present invention relates to the in situ declogging of vacuum collets blocked with solder during semiconductor chip solder bonding operations.
BACKGROUND OF THE INVENTION
Semiconductor laser chips are soldered to optical subassemblies. Often a vacuum collet is used to move the chip into position and hold it there for soldering to the subassembly. The collet is generally moved by a mechanical handler, such as a robotic arm. During use, the vacuum collet may become clogged with solder.
A clogged collet has diminished usefulness, and so the clog must be removed. Conventionally, the collet must be disengaged from the robotic arm, cleaned, and reinstalled. Collets which cannot be cleaned must be replaced.
Various conventional methodologies have been used to clean solder from vacuum collets. For example, a clogged collet may be immersed in an ultra/megasonic bath. Alternatively, high pressure air may be used to attempt to remove the clog. Further, the clog may be dislodged through mechanical means, such as with a fine probe tip.
The conventional methodologies have certain disadvantages. For example, each of the above conventional methods requires that the clogged collet be removed from the handler. This adds time to the processing of the chips. Further, none of the conventional methods are insured of removing all the solder from a clogged collet or solder from every clogged collet. Failure to remove all the solder from a collet prevents that collet from regaining its full work piece holding capability. Failure to remove the clog from the collet also may require replacement of the collet, thus adding to the cost of processing semiconductor chips.
There thus exists a need for a simple apparatus and a method for declogging collets without removing the collets from the processing line.
SUMMARY OF THE INVENTION
The present invention provides a collet declogging apparatus including a collet with a channel and a substrate. During normal use, the channel becomes at least partially blocked by a meltable material, e.g., solder. A preform of the meltable material, e.g., solder is located on the substrate. A heating source is provided for melting the meltable material in the collet and for melting the preform material. The collet is positioned by a collet handler such that the heated meltable material clogging the channel and the perform melted mass join together into a common melted mass. A cooling source then cools the melted mass. The collet is removed by the collet handler from the cooled, and now solidified, material mass free of clogs.
The present invention also provides method of unblocking a collet clogged with solder. The method includes contacting a clogged collet with a preform of solder material, melting the preform and the solder into a single melted mass, cooling the single melted mass into a cooled mass, and moving the collet away from the cooled mass.
REFERENCES:
patent: 4923521 (1990-05-01), Liu et al.
patent: 404277633A (1992-10-01), None
patent: 409298262 A (1997-11-01), None
Dautartas Mindaugas F.
Freund Joseph Michael
Przybylek George John
Romero Dennis Mark
Dickstein , Shapiro, Morin & Oshinsky, LLP
El-Arini Zeinab
Lucent Technologies - Inc.
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