Patent Application
20070272280
This invention relates generally to manufacturing microelectronic devices and, more particularly, to a system and method for spray cleaning ceramic packages.
Ceramic packages and substrates are often used to package microelectronic devices such as integrated circuits and digital micro-mirror devices (“DMDs”). Typically, these ceramic packages or substrates are manufactured separately from the microelectronic device they are used to package and then coupled with the device at a later time. Prior to using the ceramic package or substrate to package a microelectronic device, the ceramic package or substrate is cleaned to remove any debris or chemical residue leftover from manufacturing. Typically, this is accomplished by exposing the ceramic packages to a chemical bath comprising ammonium hydroxide, hydrogen peroxide, and water. After the chemical bath, the packages are then rinsed to remove any chemicals leftover from the bath, and spun dry under a nitrogen flow.
Although widely used, these chemical baths suffer from a variety of problems that can affect production yields. For example, the concentration of the chemical bath can change over time as chemicals, such as ammonium hydroxide, react with debris on the surface of the ceramic packages and/or leave solution due to evaporation. Additionally, chemical baths can become contaminated with debris from previous cleaning runs that remain suspended in the solution. Moreover, the process of bathing, rinsing, and drying the ceramic packages (and the waiting time between each step) allows several opportunities for waterspots to form on the surface of the ceramic packages before the packages are properly dried.
In accordance with the teachings of the present invention a system and method for spray cleaning ceramic packages are provided. In a particular embodiment, the system comprises a process chamber, a turntable operable to rotate within the process chamber, at least one cassette operable to be coupled with the turntable and configured to hold one or more ceramic packages, and a spray post operable to distribute a cleaning solution onto the one or more ceramic packages. In a particular embodiment, the method comprises loading a plurality of digital micro-mirror device ceramic packages into a process chamber of a spray cleaning system, spraying the ceramic packages inside the process chamber with a cleaning solution, rinsing the ceramic packages inside the process chamber with a rinse solution comprising water, draining the process chamber of the cleaning solution and rinse solution, and drying the ceramic packages inside the process chamber.
A technical advantage of particular embodiments of the present invention may include higher production yields compared to traditional methods of cleaning ceramic packages. By utilizing a single-chamber spray cleaning system, particular embodiments of the present invention are less susceptible to waterspotting that could lower production yields. Furthermore, due to the use of spray cleaning rather than traditional chemical baths, particular embodiments of the present invention may also be less susceptible to having debris from the ceramic packages contaminate the cleaning solution and/or may offer more consistent cleaning solution concentrations.
Another technical advantage of particular embodiments of the present invention may include improved cleaning efficiency. By utilizing spray cleaning rather than traditional chemical baths, particular embodiments of the present invention are able to provide more efficient cleaning through the use of both chemical and physical action.
It will be understood that the various embodiments of the present invention may include some, all, or none of the enumerated technical advantages. In addition other technical advantages of the present invention may be readily apparent to one skilled in the art from the figures, description, and claims included herein.
For a more complete understanding of the present invention and features and advantages thereof, reference is now made to the following description, taken in conjunction with the accompanying drawings, in which:
In accordance with the teachings of the present invention a system and method for spray cleaning ceramic packages are provided. In a particular embodiment, the system comprises a process chamber, a turntable operable to rotate within the process chamber, at least one cassette operable to be coupled with the turntable and configured to hold one or more ceramic packages, and a spray post operable to distribute a cleaning solution onto the one or more ceramic packages. In a particular embodiment, the method comprises loading a plurality of digital micro-mirror device ceramic packages into a process chamber of a spray cleaning system, spraying the ceramic packages inside the process chamber with a cleaning solution, rinsing the ceramic packages inside the process chamber with a rinse solution comprising water, draining the process chamber of the cleaning solution and rinse solution, and drying the ceramic packages inside the process chamber. By spraying cleaning ceramic packages, particular embodiments of the present invention may provide higher production yields and/or more efficient cleansing than traditional methods of cleaning ceramic packages.
In particular embodiments, spray cleaning system 100 also includes a mixing manifold 112 operable to mix the cleaning solution prior to application to the ceramic packages. In particular embodiments, mixing manifold 112 may mix different chemicals into a desired cleaning solution. For example, in particular embodiments, mixing manifold 112 may be used to prepare a cleaning solution comprising ammonium hydroxide, hydrogen peroxide, and water in a 1:1:10 ratio. In other embodiments, spray cleaning system 100 may forego the use of a dedicated mixing manifold 112 and may instead utilize pre-mixed cleaning solutions. The cleaning solution, whether pre-mixed or supplied by mixing manifold 112, is then supplied, to central spray post 108 and/or side-bowl spray post 110, along with any necessary water or nitrogen, for distribution within process chamber 102.
After application of the cleaning solution, process chamber 102 may be drained of the cleaning solution. Central spray post 108 and/or side-bowl spray post 110 may then be used to apply rinse solution comprising water to the ceramic packages. This helps remove any cleaning solution that might have been left on the ceramic packages from the spray cleaning. After the ceramic packages have been rinsed with the rinse solution, the rinse solution is also drained from process chamber 102. Turntable 104 may then be used to spin-dry the ceramic packages. In particular embodiments of the present invention, this may be done under a nitrogen flow to help prevent waterspotting. After the ceramic packages are spun-dry, cassettes 106 may be removed from process chamber 102, and the ceramic packages may be removed from the cassettes 106. Thereafter, the ceramic packages may be used to package microelectronic devices, such as integrated circuits and DMDs.
A better understanding of the present invention may be had by making reference to
By spray cleaning ceramic packages as described above, particular embodiments of the present invention are able to offer production yields higher than those seen with traditional chemical bath cleaning processes. Unlike traditional chemical bath-based cleaning methods, particular embodiments of the present invention are able to offer more consistent concentrations of the cleaning solution due the fact that the cleaning solutions are left exposed to the atmosphere. Particular embodiments of the present invention may also require a smaller amount of cleaning solution due to the more effective cleaning of the spray action. Particular embodiments of the present invention may also utilize equipment that has a smaller footprint than equipment used for traditional chemical bath-based cleaning systems, reducing the total amount of floor space required for the ceramic package cleaning system.
Although particular embodiments of the method and apparatus of the present invention have been illustrated in the accompanying drawings and described in the foregoing detailed description, it will be understood that the invention is not limited to the embodiments disclosed, but is capable of numerous rearrangements, modifications, and substitutions without departing from the spirit of the invention as set forth and defined by the following claims.
